Encoding of plant odours by receptor neurons in the pine weevil (Hylobius abietis) studied by linked gas chromatography-electrophysiology

Receptor neuron responses to plant volatiles, trapped by head-space procedures, were examined in the pine weevil Hylobius abietis, using gas chromatography linked with electrophysiological recordings from single neurons. Seventy-two receptor neurons were tested 173 times for various plant volatile mixtures, either via a polar or a non-polar column.

1. All responses appeared as increased firing rates which followed the concentration profiles of the GC-eluted compounds.
2. The neurons were classified separately for the two column types in 17 and 19 groups respectively, according to the compounds they responded to. It suggests that the plant odour information is encoded by a large, but limited number of receptor neuron types.
3. Most neurons responded to a limited number of compounds (1–5) and showed a marked best response to one of them, whereas additional responses to several other components which seems to be structurally similar, was recorded for some neurons. It suggests that the plant odour receptor neurons are rather narrowly than broadly tuned, and that each neuron is specialized for receiving information about one or a few related compounds.
4. Most neurons responded to monoterpenes, whereas the other neurons responded to compounds of other categories.
5. Both major and minor plant volatile components activated specifically receptor neurons.

     

Experimental problems using electronic particle counters

The following scheme lists the problems which have been and will continue to be encountered in grazing experiments on natural particle assemblages. In some cases there are solutions, but many of the problems listed below remain intractable. To solve them will require innovative approaches, most probably combining the use of particle counters with other techniques to approach the problem to be solved from several angles at once. Variance between samples due to

- statistical causes (especially caused by large particles) and

- differences between experimental bottles and between experimentals and controls at start of experiment. Shifts in particle distribution during experiment due to

- increase in small particles

- growth of bacteria and other organisms due to excretion of grazers and

- breakage during handling by grazers into fragments. Processes, independent of grazing, leading to changes in particle size distribution due to

- primary production

- grazing by additional components and

- bacterial growth on detrital particles and the formation of detrital flocs.

     

Effects of the discharge of thermal effluent from a power station on Lake Wabamun,Alberta, Canada — The epipelic and epipsamic algal communities

1. The epipelic algal standing crops were increased by the discharge of thermal effluent into Lake Wabamun, particularly in the discharge canal at station (03–04) and 05.
2. The increase in the standing crop size of the epipelon was due to Oscillatoria amoena and O. borneti in the heated area, while the discharge canal provided the inoculum of the algae for the heated area of the lake.
3. At station (03–04) the increased standing crop size was also a function of increased light penetration to the sediment due to the heated effluent keeping an area of the lake free of ice during the winter.
4. The species composition of the diatoms was similar at all stations except in the discharge canal where there was a reduction in the number of diatom species.
5. Navicula cuspidate developed best in the discharge canal in the summer where water temperatures of 31°C were recorded.
6. Amphora ovalis var. pediculus was the dominant diatom species during the winter under ice-cover.
7. The heated effluent had no effect upon the standing crop or species composition of the epipsammon.
8. Results obtained from the sediment core study showed that the shallow littoral zone of the lake is very disturbed due to wind-induced wave action.

     

Indications de l’imagerie dans l’infertilité masculine (bourses,testicules)

Imaging modalities in the work up of male infertility are almost resumed to Ultrasound with Color Doppler which is quite performant if its indications are well-balanced:

-To look for abnormalities of the seminal tract.

-To evaluate clinical varicoceles (Testis, associated abnormalities).

-To screen the neoscrotal pouchs of ectopic operatively corrected Testis (occult tumor, epididymal abnormalities).

     

Concerning variability in the delimitation of the vascular system in root primordia of maize embryos

1. The transfer of immature embryos from maternal plants to artificial media influenced the radial arrangement of vascular bundles in developing root primordia. The variability in the number of poles of the prospective protoxylem and protophloem, observed as a rule during embryogenesis under natural conditions, could not be suppressed even under the conditions ofin vitro cultivation. The possibility is admitted that when using agar medium the nutrient supply need not necessarily be equivalent for all embryos.
2. Using excised embryos of various ages the period of delimination of the vascular system in the root primordium was determined. It is relatively short and occurs in the first half of embryogenesis. The results obtained revealed no relationship between vascular system arrangement in root primordium and mature grain and mature embryo size.
3. Maize ear represents a type of inflorescence of which the apical part is delayed in development. Histogenically this uneven development becomes evident with the formation of a significantly lower mean number of poles in root primordia from the grains originating from the apical region of the cob. This is further evidence of the adaptibility of the vascular system development to environmental conditions.
4. As further causes of the variability in pole number those differences are considered which occur during sex cell formation, pollination and fertilization.

     

Beta irradiation may induce stereoselectivity in the crystallization of optical isomers

A novel approach has been introduced to detect the manifestation of symmetry breaking weak interactions at molecular level. In the racemic conglomerate crystallization of D, L-sodium-ammonium tartrate the effect of³²P irradiation was studied by measuring the weight and optical purity of the crystalline phase as well as the size distribution of the crystallites. The high number of independent experiments (over 1000) permitted statistical analysis of the results. The following observations have been made:

1. Beta irradiation influences the crystallization process, irradiated samples yield more crystalline material.
2. The effect involves presumably crystal seed formation because from the irradiated solutions more and smaller crystallites are formed.
3. The presence of beta particles induces stereoselective crystallization, the crystalline phase shows optical activity characteristic of the “unnatural” L-isomer.
4. The above changes are attributed to the beta irradiation as the magnitude of the effects depends on the amount of added radioactivity. Optically active contaminants are highly unlikely sources of the differences between irradiated and control series.
5. In the absence of³²P the tartrate enantiomers have equal probability to form crystals, i.e., the contribution of mixing of weak interaction into the electromagnetic one is not measurable in this system.

     

Age-at-death diagnosis and age-at-death distribution estimate: Two different problems with many aspects in common

A quantitative or qualitative trait detected on human skeletons can be used to solve two inferential problems:

1. Diagnosing age-at-death
2. Estimating age-at-death distribution in the human community which the skeletons belong to.

The Bayesian solutions of A) and B) are rather different and we think useful an accurate discussion about that subject.     

Water balance of small lactating rodents —III. Estimates of milk production and water recycling in lactating Mus musculus under various water regimes

1. The exchanges of water between lactating female and young Mus musculus were modelled on the computer.
2. The model was used to estimate rates of milk production and water recycling in various litter sizes under various water regimes by following the time course of injected tritiated water.
3. The high correlation between estimated rates of milk production and actual growth rates of young was taken to indicate that the method gave if not the actual rates of milk production a very constant proportion of it.
4. Approximately 50% of the water secreted in milk is returned to the mother by recycling.

     

Field studies on the variability of populations of Aster tripolium L. in relation to saltmarsh zonation

1. Aster tripolium is a very variable species of which a number of types have been described both on a morphological and ecological level.
2. In permanent plots along the height gradient in the salt marsh it appeared that differences in the A. tripolium subpopulations occur.
3. In the lowest zone of the marsh, dominated by Spartina anglica (Spartinion), the mean life expectancy of individual adult plants is relatively high but it is relatively low for seedlings.
4. In the higher zones of the marsh the mean life expectancy is relatively lower, but for the seedlings it is higher (Puccinellion maritimae).
5. In the Spartina-zone individual A. tripolium plants have about twice the number of shoots as the plants from the other zones.
6. The plants from the Spartina zone produce per individual more generative shoots (absolute) but these have less capitula than elsewhere in the marsh. The number of ripe seeds per head is almost constant everywhere in the marsh.

     

The effect of starvation on energy turnover and protein metabolism in Ophiocephalus punctatus bloch

1. At 20°C, fish starved for various durations took less food than unstarved fish. At 28°C, 20-day starved fish alone consumed more food.
2. The maximum feeding was during the second ten days at 28°C but in the first ten days at 20°C.
3. Absorption efficiency was unaffected by temperature and starvation.
4. Absorption rate reflected feeding rate.
5. At 28°C the conversion efficiency was high for the ten-day starved fish but at 20°C the 30-day starved fish showe high conversion efficiency.
6. Conversion rate is governed not only by feeding rate but also by conversion efficiency.
7. At 28°C the 20-day starved fish alone compensated for loss of energy, total and protein nitrogen. At 20°C the loss was compensated for by all fish.

     

Length dependent state of activation — Length change dependent kinetics of cross bridges in skinned insect flight muscle

Stretch induced activation and release induced deactivation of single glycerol-extracted insect flight muscle fibres were investigated. The results are interpreted to indicate that the muscle length controls the number of acting cross bridges, whereas their attachment-detachment kinetics in mainly determined by the state of strain of the cross bridges. It is concluded that the net detachment rate of the cross bridges is enhanced if the muscle is released thereby “unloading” the cross bridges. This behaviour of the unloaded cross bridge is a basic postulation of most of the molecular muscle contraction models.

1. The delayed tension rise induced by stretches of different amplitudes could be restored to the level before the stretch by a release to the initial length.
2. The delayed tension decrease induced by a release of moderate (up to δL=1.5% L _i)amplitude is quantitatively restored within the delayed increase induced by the restretch to the initial length.
3. Stiffness, which decreased during the delayed tension drop after release, is restored during a delayed stiffness increase effected by a restretch to the initial length.
4. The rate and the extent of the stiffness drop after release increased with increasing amplitude of the release and with increasing temperature.
5. After the deactivation, i.e., after tension and stiffness achieved a new steady level after the release, the attached cross bridges are already in the same state of strain as they were before the release. This finding is interpreted to indicate that within the deactivation phase all cross bridges attached prior the release are replaced by cross bridges attached after the release.
6. The rate of tension and stiffness decay after release does not depend on the absolute muscle length but on the amplitude of the release which induced the deactivation.

     

A study of the relationship between mechanical characteristics and the coastal vegetation among several broad-leaf trees in Miura Peninsula in Japan

The mechanical properties of broad-leaf tree species in a maritime-wind exposed habitat in central Japan were examined. The broad-leaf trees studied were Celtis sinensis var. japonica, Ilex integra, Eurya japonica, Pittosporum tobira, Euonymus japonicus and Cinnamomum japonicum. The results obtained can be summarized briefly as follows:

1. At places with weaker wind, the number of species increased and the height of the canopy increased.
2. The fracture strength σ_m showed no dependence on tree part or branch thickness, but was constant.
3. The order of strength was Celtis sinensis var. japonica > Ilex integra > Eurya japonica > Pittosporum tobira > Euonymus japonicus > Cinnamomum japonicum, and these six species could best adapt to the wind pressure in the study area.
4. Within species, fracture strength varied directly with wind strength.
5. The strain ε_m decreased as the trunk became thicker.
6. Within species, strain energy U_m varied directly with wind strength.

     

Les brisures de symetrie du temps

Introduction

Atoms theory and symmetry theory dominated physics. Symmetry propagation and interactions verify the Curie principle. But its violation by symmetry breaking is spontaneous.Fragility is creative. An information breaks a generalized symmetry. Results on symmetry breakings are not valid for fuzzy symmetries. The breaking of a fuzzy symmetry leads only to a pour symmetry (Fig.1). Homogeneity breaking, and atom of time are not usual concepts. We examine in this work symmetry breakings which generate the living time.

Relativistic Time-Space Breaking

1. Medium and environment of living define ordinary referential of space and referential of time. Astronomical phenomena following classical mechanics and microphysical phenomena following quantum mechanics can be written with the same t coordinate.
2. Relativity corrections. Schrödinger's Quantum mechanics (Eq.0) approximately governs molecular systems (Relativity corrections can be expressed as physical effects in the above defined referential).
3. Time reversal symmetry. The well-known Wigner's transformation determines the microscopic reversibility.
4. The three essential particle-vacancy equilibria. This transformation is verified by all particle-vacancy reciprocity. Vacancy moves like particle but with negative moment and positive kinetic energies. Only three biochemical equilibria admit this time reversal symmetry, namely: oxydo-reduction, acido-basicity, fluidity-viscosity. In these case, reacting electron, solvated proton, water molecule are respectively antagonist of the corresponding vacancy.
5. Fuzzy character of time reversal symmetry. Dirac's equation does not admit this symmetry which only appears at the “non relativistic” limit of quantum phenomena. Hence particle-vacancy reciprocity is fuzzy according to the experimental evidence. (Laforgue et al., 1988).

Oriented Time

1. From the universal reversible time, an additional breaking generates the oriented time, both in the astronomical and in the living matter.
2. Irreversibility for the environment. We refer to Prigogine and Stengers (1988).
3. Irreversibility for the living matter. We refer to Lochak (1986). Because equation (0), above discussed, is “microreversible” the second breaking could come from an additional term vanishing in the stationary states but increasing with time in evolutionary processes.
4. Negative times. Taking into account the fuzzy character of the time reversed symmetry, the third breaking cannot suppress completely the occurrence of negative times. Reversed time is controlled by direct time. Except in the three above reported cases, time reversal symmetry is not verified by the medium. Free motion of the particle following eg.(0) or of the vacancy following time reversal reciprocal equation takes place only during short jumps from an interaction site to an other. Fig. 2 schematizes the law of motion of the electric charge corresponding to the transport by proton or by proton vacancy in an unitary field (fluctuations are neglected). The reserved jumps are estimated in the range of 10^?12s. It is not excluded that such a jump can control a direct phenomenon.
5. The living time. Biological phenomenon appears as an oriented set of events. Nevertheless latency or exaltation phases could be perceived. This modulation could be described by positive and negative times additional to the basic time. (Negative can be interpreted as above)

Living produces Time

1. That were not understandable, if time was only a frame, in which change occurs. Taking chance as frame and time as effect, we regard biological activity as integrating reversible and irreversible time. Living synchronizes internal and external time by its own effort as it results (Lestienne, 1990) from Chronobiology.
2. Time modulation. Let us consider the dy₁...dy_i...dy_p changes in the variables of the systems, dy={dy_i} has produced dt. We proof (eq.(1) to (4)) that time is modulated by a φ_(y) speed coefficient depending on the medium. t_modulated=tφ _(y) ^?1
3. The production of reversible time (e.g.acido-basicity) determines time modulation. As above reported it remains some reversibility effects (jumps of negative time) which modulate time. E.G., if an important amount of reagent is necessary to modify an acid-base equilibrium, φ_(y) is small.
4. Time modulation and activation-repression reciprocity. As well-known, long t_modulated means repression, short t_modulated means exaltation. Extrema of ? are symmetrical because particle and vacancy are reciprocal. Nevertheless reciprocity is not perfect. E.g., on fig. 3, the wet receptor determines the cell increasing, the dry receptor the cell senescence of a certain alga (Lück, 1962).
5. Irreversible time production. Medium accepts entropy. Hence it acts in the second breaking of time. Living extracts the free energy from the medium, like a dissipative structure. That insures an operative point far from the thermodynamical equilibrium.

Consumption of Time

1. The three followings correspond to the more trivial time consumption.
2. Rhythmical time. Free energy flux is favourable to the arising of order in space or time. This later gives a structure to the living time.
3. Mutual dependence of reversible time and rhythms. Time irreversible structure can be controlled by the above considered particle-vacancy equilibrium. Consequently the living time (modulated and structured) is a chemical time connected to molecular properties and to statistical thermodynamics. Practically, the connection between chronobiology and chemistry is important. The use of drugs could be interpreted as a response to an aggression against biorhythms.
4. Lifetime. The dead-birth rythm can be broken in two ways: evolution or indefinite life. This later is non exceptional for the living matter, e.g. in the vegetals where it is connected with the chlorophyllic assimilation; the time reversal significance of which is evident.
5. The plan of the alchemist. Indefinitely life has fascinated individuals. Do the human species becomes better adapted by a longer life?

Conclusions

1. Atoms of time could exist.
2. Biological time is defined by the breaking of five generalized symmetries, namely: Minkovski's space symmetry, reversibility, homogeneity, rhythmicity, generations reproduction.
3. Environment and medium determine non relativistic, oriented, structured time.
4. At the microphysical scale, a fuzzy time reversal symmetry takes place, the breaking of which is not complete. Reversible time and dominating irreversible time are integrated in living phenomena.
5. Three fundamental particle-vacancy reciprocities admit a part of reversibity. Irreversibility governs the all others phenomena.
6. Time is produced chemically.
7. A new perspective is the connection between chemical equilibria and rhythms including the time of the life.

     

A study on the rate of water transport of the clam katelysia opima in relation to environmental conditions

1. The neutral red technique was employed to study the rate of filtration in Katelysia opima.
2. The weight specific water filtration was found to be greater for younger clams compared to the older ones.
3. The rate of water filtration increased with decreasing salinity.
4. Water filtration was found to increase as temperature increased, reaching a maximum at 35°C. but then sharply decreasing at 39°C.
5. Light had no significant effect on the rate of filtration.
6. Suspended matter was found to affect the rate of water filtration.
7. The rate of filtration was low at high pH and high in low pH.
8. The rate of water filtration was found to be faster during high tide than during low tide.
9. The presence of the parasitic crab, Pennotheris sp., in the mantle cavity of clams had a marked effect on the particle filtration.
10. Accidental cut of the siphon tips had no effect on the rate of filtration.

     

Les brisures de symetrie du temps

Introduction

Atoms theory and symmetry theory dominated physics. Symmetry propagation and interactions verify the Curie principle. But its violation by symmetry breaking is spontaneous.Fragility is creative. An information breaks a generalized symmetry. Results on symmetry breakings are not valid for fuzzy symmetries. The breaking of a fuzzy symmetry leads only to a pour symmetry (Fig.1). Homogeneity breaking, and atom of time are not usual concepts. We examine in this work symmetry breakings which generate the living time.

Relativistic Time-Space Breaking

1. Medium and environment of living define ordinary referential of space and referential of time. Astronomical phenomena following classical mechanics and microphysical phenomena following quantum mechanics can be written with the same t coordinate.
2. Relativity corrections. Schrödinger's Quantum mechanics (Eq.0) approximately governs molecular systems (Relativity corrections can be expressed as physical effects in the above defined referential).
3. Time reversal symmetry. The well-known Wigner's transformation determines the microscopic reversibility.
4. The three essential particle-vacancy equilibria. This transformation is verified by all particle-vacancy reciprocity. Vacancy moves like particle but with negative moment and positive kinetic energies. Only three biochemical equilibria admit this time reversal symmetry, namely: oxydo-reduction, acido-basicity, fluidity-viscosity. In these case, reacting electron, solvated proton, water molecule are respectively antagonist of the corresponding vacancy.
5. Fuzzy character of time reversal symmetry. Dirac's equation does not admit this symmetry which only appears at the “non relativistic” limit of quantum phenomena. Hence particle-vacancy reciprocity is fuzzy according to the experimental evidence. (Laforgue et al., 1988).

Oriented Time

1. From the universal reversible time, an additional breaking generates the oriented time, both in the astronomical and in the living matter.
2. Irreversibility for the environment. We refer to Prigogine and Stengers (1988).
3. Irreversibility for the living matter. We refer to Lochak (1986). Because equation (0), above discussed, is “microreversible” the second breaking could come from an additional term vanishing in the stationary states but increasing with time in evolutionary processes.
4. Negative times. Taking into account the fuzzy character of the time reversal symmetry, the third breaking cannot suppress completely the occurrence of negative times. Reversed time is controlled by direct time. Except in the three above reported cases, time reversal symmetry is not verified by the medium. Free motion of the particle following eg.(0) or of the vacancy following time reversal reciprocal equation takes place only during short jumps from an interaction site to an other. Fig. 2 schematizes the law of motion of the electric charge corresponding to the transport by proton or by proton vacancy in an unitary field (fluctuations are neglected). The reserved jumps are estimated in the range of 10^?12s. It is not excluded that such a jump can control a direct phenomenon.
5. The living time. Biological phenomenon appears as an oriented set of events. Nevertheless latency or exaltation phases could be perceived. This modulation could be described by positive and negative times additional to the basic time. (Negative can be interpreted as above.)

Living produces Time

1. That were not understandable, if time was only a frame, in which change occurs. Taking change as frame and time as effect, we regard biological activity as integrating reversible and irreversible time. Living synchronizes internal and external time by its own effort as it results (Lestienne, 1990) from Chronobiology.
2. Time modulation. Let us consider the dy₁...dy_i...dy_p changes in the variables of the system, dy={dy_i} has produced dt. We proof (eq.(1) to (4)) that time is modulated by a Φ_(y) speed coefficient depending on the medium. t_modulated=tΦ^-1 _(y)
3. The production of reversible time (e.g.acido-basicity) determines time modulation. As above reported it remains some reversibility effects (jumps of negative time) which modulate time. E.g., if an important amount of reagent is necessary to modify an acid-base equilibrium, Φ_(y) is small.
4. Time modulation and activation-repression reciprocity. As well-known, long t_modulated means repression, short t_modulated means exaltation. Extrema of ? are symmetrical because particle and vacancy are reciprocal. Nevertheless reciprocity is not perfect. E.g., on fig. 3, the wet receptor determines the cell increasing, the dry receptor the cell senescence of a certain alga (Lück, 1962).
5. Irreversible time production. Medium accepts entropy. Hence it acts in the second breaking of time. Living extracts the free energy from the medium, like a dissipative structure. That insures an operative point far from the thermodynamical equilibrium.

Consumption of Time

1. The three followings correspond to the more trivial time consumption.
2. Rhythmical time. Free energy flux is favourable to the arising of order in space or time. This later gives a structure to the living time.
3. Mutual dependence of reversible time and rhythms. Time irreversible structure can be controlled by the above considered particle-vacancy equilibrium. Consequently the living time (modulated and structured) is a chemical time connected to molecular properties and to statistical thermodynamics. Practically, the connection between chronobiology and chemistry is important. The use of drugs could be interpreted as a response to an aggression against biorhythms.
4. Lifetime. The dead-birth rhythm can be broken in two ways: evolution or indefinite life. This later is non exceptional for the living matter, e.g. in the vegetals where it is connected with the chlorophyllic assimilation; the time reversal significance of which is evident.
5. The plan of the alchemist. Indefinitely life has fascinated individuals. Do the human species becomes better adapted by a longer life?

Conclusions

1. Atoms of time could exist.
2. Biological time is defined by the breaking of five generalized symmetries, namely: Minkovski's space symmetry, reversibility, homogeneity, rhythmicity, generations reproduction.
3. Environment and medium determine non relativistic, oriented, structured time.
4. At the microphysical scale, a fuzzy time reversal symmetry takes place, the breaking of which is not complete. Reversible time and dominating irreversible time are integrated in living phenomena.
5. Three fundamental particle-vacancy reciprocities admit a part of reversibility. Irreversibility governs the all others phenomena.
6. Time is produced chemically.
7. A new perspective is the connection between chemical equilibria and rhythms including the time of the life.

     

Survival,osmoregulatory ability,and respiration of idotea chelipes (Crustacea,Isopoda) from lake veere in different salinities and temperatures

1. An ecological and physiological study ofI. chelipes from Lake Veere, The Netherlands, was made.
2. Both osmoregulatory capacity and survival decrease with increasing temperature as well as with decreasing salinity.
3. Respiration experiments suggest that the need of energy by osmoregulatory activity may be supplied at the cost of other physiological processes, at any rate at temperatures of 10°C and higher.
4. It may be expected that, if temperatures higher than 15°C and salinities lower than 8‰ coincide, the population ofI. chelipes will be affected negatively.

     

The chemical identification of root promoters extracted from avocado tissues

From the Avocado Rooting Promoter (ARP) 4 compounds were isolated and identified as:

1. 1 acetoxy - 2,4 dihydroxy-n-heptadeca-16-en;
2. 1 acetoxy - 2,4 dihydroxy-n-heptadeca-16-yn;
3. 1,2,4 trihydroxy-n-heptadeca-16-en;
4. 1,2,4 trihydroxy-n-heptadeca-16-yn.

The rooting activity of the pure compounds was verified using the mung bean rooting bioassay. Compound 2II is the most active.     

Cocaine kindling in mice

Previous studies proposed the involvement of theN-methyl-D-aspartate (NMDA) type of glutamate receptors in the development of sensitization to the convulsive effect of cocaine (cocaine kindling). The present study was undertaken to determine, first, if cocaine kindling is associated with enhanced sensitivity of the NMDA receptor to the convulsive response ofN-methyl-D,L-aspartate (NMDLA), and second, whether in vivo modulation of nitric oxide synthase (NOS) function regulates the development of cocaine kindling. The following results were observed:

1. Cocaine-kindled animals were significantly more susceptible to the convulsive effect of the NMDA receptor agonist NMDLA than saline controls;
2. Pretreatment with the NOS inhibitor N^G-nitro-L-arginine methyl ester (L-NAME; 100 mg/kg; ip) blocked the development of cocaine kindling;
3. The protective effect of L-NAME was partially reversed with the coadministration of the NOS substrate,L-arginine (300 mg/kg; ip), but notD-arginine; and
4. L-Arginine (300 mg/kg; ip), but notD-arginine, amplified the development of cocaine kindling. Taken together, these findings suggest that supersensitivity of the NMDA receptor and activation of NOS may underlie the development of cocaine kindling.