c-Fos-related antigens in the central nervous system of an insect, Acheta domesticus

Fos-related antigens (Fra) were detected in the nuclei of neurones in young adult Acheta domesticus female crickets by immunohistochemical analysis, using an antibody that recognizes the amino-acid sequence 127-152 of c-Fos protein. Specificity of Fra immunoreactivity was confirmed by Western blot analysis of nuclear extracts from neural tissues. A major immunoreactive doublet with an apparent molecular mass of 52,000/54,000 Da was detected in nuclear extracts. Immunostaining of the 52,000/54,000 Da doublet showed variations in intensity during the first 5 days following the imaginal molt. Staining was more intense between day 2 and day 4 when ecdysteroid titers were high. Expression of Fra was low in allatectomized (i.e., deprived of juvenile hormone and ecdysteroids) and ovariectomized (i.e., deprived of ecdysteroids) females as compared to control females. These results show the involvement of hormone-regulated process in expression of Fra. The effect of nociceptive stimulation on Fra expression was tested. Twenty minutes after removal of the ovipositor, a supplementary band with an apparent molecular mass of 70,000 Da appeared in the nuclear extracts, then decreased and disappeared totally after 45 min. Several other Fos-related antigens with different temporal patterns of expression were also detected.     

Circadian rhythm in acetylcholinesterase activity during aging of the central nervous system

The circadian rhythm of acetylcholinesterase (AChE) activity was investigated in the cerebrum, cerebellum, medulla and optic lobes of rats aged 1 day and 3, 13, 44 and 87 weeks. The rhythm was found to be age-dependent. Animals aged 1 day exhibited a bimodal rhythm in all the four regions of the brain studied. At 3 and 13 weeks the activity was unimodal. The peak occurred during the light-on phase at 3 weeks and during the light-off phase at 13 weeks. At 87 weeks the rhythms in the medulla and cerebrum were similar to those of 44 week animals. By contrast the cerebellum had a bimodal rhythm with peaks at intervals of 12 h. In the optic lobes there was a shift from a bimodal pattern at 44 weeks to a unimodal one at 87 weeks. The times of onset of the light-on and light-off peaks in different regions of the brain differed with age.     

The stomatogastric nervous system of the house cricket Acheta domesticus L. II. Iontophoretic study of neuron anatomy

The anatomy of neurons of the stomatogastric nervous system of Ascheta domesticus was studied using heavy metal iontophoresis through cut nerve ends followed by silver intensification. Nineteen categories of neuron are described and compared with neurons known from the stomatogastric nervous system of other insects. Possible functions for the neurons are suggested. Motor neuron candidates are suggested for all parts of the gut served by the stomatogastric nervous system, and axons of sensory neurons of the anterior pharynx are located. There are four neuron types that cannot readily be assigned motor, sensory, or interneuron functions: large dorsal cells of the frontal ganglion; the two neurons of the nervus connectivus, and two categories of neurons in the median neurosecretory cell group of the pars intercerebralis, the axons of which are contained in the stomatogastric nerves.     

A circadian rhythm in neural activity can be recorded from the central nervous system of the cockroach

Summary Evidence presented in this paper indicates that a robust circadian rhythm in the frequency of neural activity can be recorded from the central nervous system of intact cockroaches, Leucophaea maderae. This rhythmicity was abolished by optic lobe removal. Spontaneous neural activity was then used as an assay to demonstrate that the optic lobe is able to generate circadian oscillations in vitro. These results provide direct evidence that the cockroach optic lobe is a self-sustained circadian oscillator capable of generating daily rhythms in the absence of neural or hormonal communications with the rest of the organism.Abbreviations CNS central nervous system - DD constant dark - LD light/dark cycle - SCN suprachiasmatic nucleus - ZT Zeitgeber time     

Serotonin phase-shifts the circadian rhythm of locomotor activity in the cockroach

Serotonin, a putative neurotransmitter in insects, was found to cause consistent phase shifts of the circadian rhythm of locomotor activity of the cockroach Leucophaea maderae when administered during the early subjective night as a series of 4-microliters pulses (one every 15 min) for either 3 or 6 hr. Six-hour treatments with dopamine also caused significant phase shifts during the early subjective night, but 3-hr treatments with dopamine had no phase-shifting effect. Other substances tested in early subjective night (norepinephrine, octopamine, gamma-aminobutyric acid, glutamate, carbachol, histamine, tryptophan, tryptamine, N-acetyl serotonin, or 5-hydroxyindole-3-acetic acid) did not consistently cause phase shifts. The phase-shifting effect of serotonin was found to be phase-dependent. The phase response curve (PRC) for serotonin treatments was different from the PRC for light. Like light, serotonin caused phase delays in the late subjective day and early subjective night, but serotonin did not phase-shift rhythms when tested at phases where light causes phase advances.     

The stomatogastric nervous system of the house cricket Acheta domesticus L. I. The anatomy of the system and the innervation of the gut

The distribution of the ganglia and nerves of the stomatogastric nervous system and the innervation of the extrinsic and intrinsic muscles are described. Median unpaired frontal and hypocerebral ganglia and paired ingluvial ganglia are present. The anterior pharynx is innervated by branches of the frontal nerve and by the anterior and posterior pharyngeal nerves, originating from the frontal ganglion. The posterior pharyngeal nerves are linked to nerves innervating the posterior part of the pharynx which have their origin in the hypocerebral ganglion, the anterior portion of which has previously been regarded as part of the recurrent nerve. Paired esophageal nerves run the length of the esophagus and crop between the hypocerebral and and ingluvial ganglia, innervating the muscularis by serial side branches. From each ingluvial ganglion runs an ingluvial nerve which innervates the gizzard and a cecal nerve which innervates the midgut and its ceca. At the posterior end of the midgut there is a poorly developed nerve ring. Nerves running posteriorly from this nerve ring link the stomatogastric nervous system with the proctodeal innervation from the terminal abdominal ganglion. Multipolar peripheral neurons are present on the muscularis of the whole of the foregut, rather randomly distributed on the crop and gizzard but forming fairly definite groupings at some points on the pharynx. Though of varied appearance, these cells could not be divided into discrete morphological categories. Peripheral neurons on the midgut are of different and characteristic morphology, though a few cells of the same appearance as those of the foregut occur at the midgut-hindgut boundary. Nerve fibers on the gut almost invariably terminate on the fibers of the muscularis.     

Control of the circadian rhythm of locomotor activity in the house cricket

A detailed analysis was made of the locomotor activity of Acheta domesticus under conditions of 12 hr light and 12 hr darkness (LD 12 : 12) and of continuous darkness (DD). Under LD 12 : 12 it was found that there are three types of insects: (1) those beginning the period of increased locomotor activity immediately after darkness falls, (2) considerably before this time, and (3) considerably after this time. Under DD conditions the greater amount of the insects have a free-running rhythm shorter than 24 hr, while only a small percentage have a rhythm of more than 24 hr.Destruction of the neurosecretory cells of the pars intercerebralis by means of radio waves leads to the formation of hyperactivity and loss of locomotor activity rhythm when more than half of these cells are destroyed.Injection of reserpine into the insect's haemolymph with doses of 10 μg/g of body weight results in a reduction in locomotor activity and produces arrhythmicity for 2 to 3 days under LD 12 : 12 conditions. Under DD conditions, however, this same dose results in a total and irretrievable loss of free-running rhythm. Histological studies of the brain of crickets following injection of reserpine show a large degree of accumulation of neurosecretion in the cells of the pars intercerebralis as compared with control insects.A hypothesis is put forward as to the way in which the brain centres regulating locomotor rhythm act in crickets.     

Formal properties of the circadian rhythm of locomotor activity in Japanese quail

Summary Japanese quail have a circadian rhythm of locomotor activity whose free-run period () in constant darkness (DD) was 22.5±0.1 h (45). A phase response curve of typical form was obtained by illuminating the free-running rhythm with single 1 h light pulses. Using entrainment theory a derived phase response curve was calculated from the phase relationships between the locomotor rhythm and 1 h light periods in light-dark cycles of various lengths (T). Although the limits of entrainment to theseT cycles differed slightly from those predicted, there was a close correlation between the two phase response curves. The phase relationships between the locomotor rhythm and 1–9 h photoperiods in 24 h cycles were in general accord with a prediction based on the short free-run period and the relative sizes of the delay and advance portions of the phase response curve for 1 h light pulses.     

A circadian rhythm of locomotor activity in newly emerged Ceratophyllus sciurorum

Abstract Circadian rhythm in newly emerged individuals of the Red Squirrel ( Scuirus vulgaris ) flea C.s. sciurorum was studied in a constant environment, using an insect activity monitor. Trials were run over 7 days using two start times (08.00 and 17.00 hours). The results show that, regardless of start time, the fleas display a 24 h activity rhythm. The presence of a rhythm under constant conditions gives a strong indication that C. s.sciurorum has a self-sustaining clock which is started by disturbance and is most likely to be linked to host activity patterns.     

Entrainment of the circadian locomotor activity rhythm in the Japanese newt by melatonin injections

We examined whether melatonin can act as a synchronizing agent within the circadian system of amphibians by testing the ability of melatonin injections to entrain the circadian locomotor activity rhythm of a newt (Cynops pyrrhogaster). Under constant darkness, all newts (13 cases) showing the free-running rhythms were subcutaneously injected with 10 g melatonin at the same time every other day for at least 30 days. Subsequently, they were injected with vehicle (1% ethanolic saline) instead of melatonin for at least another 30 days. In 10 of the 13 newts, the locomotor activity rhythms could be entrained to a period of 24 h by melatonin injections but not by vehicle injections. During the entrained steady-state, the active phase of an activity-rest cycle preceded the time of melatonin injections as previously reported in other diurnal species. These results suggest that the endogenous circadian rhythm of melatonin concentration may be involved in synchronizing circadian oscillator(s) within the newt's circadian system.     

Glutaminase activity in the chick central nervous system during postnatal growth.

1. Glutaminase activity was evaluated in the chick cerebral hemispheres, optic lobes and cerebellum between the 1st and 30th day of postnatal growth. 2. Glutaminase activity is higher in the cerebral hemispheres than in the optic lobes and is lowest in the cerebellum. 3. It seems to be inversely related to the magnitude of the variations of glutamine concentration in the three areas. 4. No direct relation exists between enzyme activity and glutamate concentration in the three tissues.     

The effect of insulin on circadian rhythm of voluntary locomotor activity in rats

Effects of single intranasal administration of 0.2 ng insulin at different moments of the projected daily cycle (ZT = 1, ZT = 7, ZT = 13 and ZT = 19) on the circadian rhythms of voluntary locomotor activity (wheel-running) were studied in Wistar male rats. Insulin administered at ZT-7 or ZT-13 induced a statistically significant phase advance by 4.4 and 5.5 hours, respectively. The administration of insulin at ZT-13 additionally induced a reduction of the period of the circadian rhythm of voluntary locomotor activity. Intranasal administration of insulin at other moments of the projected daily cycle (ZT = 1 or ZT = 19) did not induce any statistically significant change in phase or period duration of the circadian rhythms. Insulin did not cause changes in total daily activity irrespective of administration time. The results of the study suggest the role of endogenous insulin as entrainment factor for circadian oscillator in absence of the main physiological zeitgeber--cyclic afferent input from retina photoreceptors.     

Dissociation between the circadian rhythm of locomotor activity and the pineal clock in the Japanese newt

The circadian locomotor activity rhythm of the Japanese newt has been thought to be driven by a putative brain oscillator(s) subordinate to the pineal clock. The existence of mutual coupling between the pineal clock and the brain oscillator(s) in vivo was examined. We covered the newt's skull with aluminum foil and simultaneously reversed the light-dark cycle, thereby allowing the pineal organ to be exposed to constant darkness while the rest of the animal was exposed to the reversed light-dark cycle. In control animals, whose heads were covered with transparent plastic, the rhythm of synaptic ribbon number in the pineal photoreceptor cells was entrained to the reversed light-dark cycle. Rhythms from newts whose heads were shielded, however, were similar to those observed in the unoperated newts kept under constant darkness. The locomotor activity rhythms of both head-covered animals and control animals were entrained to the reversed light-dark cycle. These data suggest that extrapineal photoreception can entrain the putative brain oscillator(s), but not the pineal clock. Thus, at least in an aspect of photic entrainment, there seems to be little or no mutual coupling between the pineal clock and the putative brain oscillator(s) in the circadian system of the Japanese newt.Abbreviations LD light-dark - DD constant darkness - SCN suprachiasmatic nucleus - SR synaptic ribbon     

Enzymatic patterns in the embryonic development of the cricket,Acheta domesticus L.

Summary The activity of the enzymes G6PDH, 6PGDH, GAPDH, LDH, CS, MDH, NADP-linked ICDH, GOT, GPT, and GLDH was tested in different stages of developing eggs and in just hatched larvae of crickets. A malic synthase could not be found. The enzymatic pattern changes considerably during this period. Considering this pattern, and especially the quotient (GAPDH)/CS, it seems justified to state that, up to the formation of the germ band, the energy is derived mainly from oxidation of glucose in the citric acid cycle. Later on, lipids substitute partly for glucose. Anaerobic energy production seems to be limited to the stage of the dorsal closure. By inhibiting the formation of the germ band, the activity of GAPDH, and CS is not changed significantly. The rise in activity of G6PDH is correlated with the increased rate of r-RNA synthesis. The increase of activity of MDH and NADP-linked ICDH corresponds to the differentiation of the germ band. These enzymes, together with GOT, GPT, and GLDH should be involved in the synthesis of amino acids from carbohydrates during the later part of development. In the hatched larvae the activity of all enzymes has risen considerably. This stage is characterized by the fact that G6PDH, 6PGDH, GAPDH, LDH, CS, and NADP-linked ICDH display the same activity.This work was supported by the Stiftung für Krebs- und Scharlachforschung (Strebelstiftung).     

Analysis of the apparent tissue specific differences in Acheta domesticus ribosomal proteins

One- and two-dimensional polyacrylamide gel electrophoresis of ribosomal proteins isolated from Acheta domesticus male accessory gland, testes and whole body show highly reproducible quantitative and qualitative differences. However, control experiments show that these differences are due either to preferential loss of some ribosomal proteins or to the binding of cell sap proteins during ribosome isolation. No differences could be detected between proteins of 0.25 M and 0.5 M KCl-washed nymph and adult accessory gland ribosomes. The protein composition of ribosomes isolated from various tissues and developmental stages of the cricket appear to be very similar.