Components of early maternal environment affecting the predisposition to catalepsy

Reciprocal pup substitution (cross-fostering) in cataleptic GC (designated so by the initials of words "genetic" and "catalepsy") and control Wistar females resulted in attenuation of cataleptic predisposition in GC rats fostered by Wistar foster-mothers. The latter demonstrate a more intense maternal care than GC females. There was a significant negative correlation between the frequency of mother staying in nest and the duration of pinch-induced catalepsy in pups fostered by her. In the home-cage retrieval test, the females of the strains compared showed a significant dependence of the latencies of approach to, and retrieval of, pups on their own and the pups' genotype.     

Effects of change of maternal environment during early postnatal development on behaviour in cataleptic rats

Pinch-induced catalepsy was compared at an age of 2 weeks and at weaning in cataleptic GC and control Wistar rats reared by their biological mothers or subjected to reciprocal in-or cross-fostering. Besides, some open-field parameters were studied in the same groups of rats at an age of 2 months. Significant interstrain differences in all the behavioural parameters studied were found. Reciprocal cross-fostering tended to diminish interstrain differences in most parameters. It brought about a decrease of duration of pinch-induced catalepsy at 2 weeks and at weaning in GC rats, and an increase of duration of catalepsy at weaning in Wistar females. Besides, cross-fostering decreased the duration of freezing in the open-field test in GC rats at 2 months.     

Effect of experimental elevation and decrease of thyroxine level on catalepsy in rats

Thyroid dysfunction is associated with mental disorders. The present study was aimed to reveal the effects of experimental decrease and increase of thyroxine level on expression of two types of extensive freezing: spontaneous and pinch-induced catalepsy, in Wistar rat males. Chronic administration of thyroxine synthesis inhibitor, propylthiouracil (5 mg/kg/day, 28 days), markedly decreased plasma hormone level and at the same time produced a significant increase in percentage of spontaneously cataleptic animals and immobility time, but had no effect on the expression of pinch-induced catalepsy. On the contrary, chronic thyroxin (0.1 mg/kg/day, 28 days) treatment produced no effect on spontaneous catalepsy expression, although it significantly increased percentage of cataleptic animals and immobility time of pinch-induced catalepsy. The results suggest that both the thyroid hormone deficit and excess provoke catalepsy in rats but enhance different forms of freezing reaction.     

Body pinch induces long lasting cataleptic like immobility in mice: Behavioral characterization and the effect of naloxone

The present article reports that repeated exposure to brief pinches at the scruff in mice results in the development of long lasting cataleptic-like immobility. The response is robust, readily induced and involves changes in autonomic functions and pain sensitivity. The development of catalepsy and the concominant antinociception are blocked by naloxone pretreatment. In contrast, naloxone fails to suppress the pinch-induced catalepsy when administered after this behavior has already been established. Taken together, the findings offer a simple and most reliable model to study the neural mechanisms that mediate “naturally occurring”, stress- induced catalepsy.     

The development of catatonic reactions in male mice of CBA/Lac strain: the effect of repeated experience of aggression and submission

The development of catatonic reactions with rigid muscle tension due to stimulation of the skin at the scruff (catatonia-"pinch" test) and wax muscle plasticity (repeated pinch-induced catalepsy displayed on the parallel bars--BAR-test) was investigated in aggressive and submissive CBA/Lac male mice with repeated experiences of social victories (winners) or defeats (losers), accordingly. The expression of catatonic-like state in "pinch" test was significantly more in the losers after 20 daily agonistic confrontations in comparison with the winners. The catalepsy in the BAR-test was increased in animals with experience of agonistic confrontation in comparison with the controls, however expression of catalepsy reaction depended on kind and duration of agonistic interactions. The pronounced freezing predominated in the free behavior of the losers and, on the contrary, the winners demonstrated the abnormal undirected jumping. It was suggested that two contrast forms of catatonic syndrome accompanying by development of akinesia- or hiperkinesia-like states, are developed in the defeated and victorious (accordingly) mice of cataleptic CBA/Lac strain.     

Involvement of striatum serotonergic system in the expression of genetically defined catalepsy

The activity of the rate-limiting enzyme of serotonin biosynthesis, tryptophan hydroxylase, and specific binding of [3H]ketanserin to 5-HT2A receptors and [3H]8-OH-DPAT to 5-HT1A receptors in the striatum of genetically predisposed to catalepsy rats and mice have been studied. The activity of tryptophan hydroxylase in the striatum of rats bred for many generations for predisposition to catalepsy was higher than in nonselected rats. Mice of highly susceptible to pinch-induced catalepsy CBA strain also differed from noncataleptic AKR and C57BL mouse strains by higher activity of tryptophan hydroxylase in striatum. Inhibition of tryptophan hydroxylase with p-chlorophenylalanine or p-chloromethamphetamine significantly decreased immobility time in genetically predisposed to catalepsy rats and mice. A decrease in the [3H]ketanserin specific binding in the striatum of cataleptic rats and CBA mice was found indicating a decrease in 5-HT2A receptor density. A decrease in [3H]8-OH-DPAT binding in striatum of cataleptic rats but not in CBA mice was shown. These results indicate that serotonergic system of striatum is involved in the expression of hereditary catalepsy and suggest that hereditary catalepsy may result from genetic changes in the regulation of serotonin metabolism and reception in striatum.     

Selection of Wistar rats for predisposition to catalepsy

Non-inbred Wistar rats were bred for predisposition to catalepsy for 14 generations. The percentage of cataleptic rats, beginning from the F1, was about 50%, while in the control population it was about 9%. This, together with the data obtained after comparison of the proportion of cataleptic animals in the progeny from homogeneous crossings between rats of normal and cataleptic phenotypes from the group selected for catalepsy (16 and 48%, respectively), makes one suppose predisposition to catalepsy to be an oligogenic character. The later onset of stereotype-like reactions to administrations of methylphenidate, and their longer persistence in cataleptic animals points to inertness of dopaminergic systems. At the same time, the increased frequency of "hyperactivity"-like reactions to methylphenidate, as well as higher arterial pressure and lower frequency of defecations seem to reflect an increased excitability of noradrenergic brain systems in rats predisposed to catalepsy.     

Some neuroendocrinological changes in rats of cataleptic strain GC. Influences of ontogenesis and generation of breeding

The content of biogenic amines: dopamine, noradrenaline and serotonine, in rats of cataleptic strain GC as compared with the control strain Wistar at the age of 1 and 5 months is decreased, the maximal decrease being found in the so-called "nervous" animals. The aldosterone content was decreased at 5 month age in the GC rats. The testosterone content at the age of 1 month in GC rats does not differ from that in Wistar rats, but at the age of 5 months it was decreased as compared to Wistar, the maximal decrease being found again in "nervous" GC rats. The data obtained point to peculiarities of ontogenetic regulation and to commonness of mechanisms of catalepsy and "nervousness" in GC rats.     

Effects of chronic imipramine treatment on behavior in mice of congenic strains AKR and AKR.CBA-D13Mit76 differing in the distal fragment of chromosome 13

Congenic mouse strain AKR.CBA-D13Mit76 carries the 59-70 cM fragment of chromosome 13 transferred from genome of cataleptic CBA/Lac strain to genome of AKR/J none-cataleptic strain. This fragment contains the major gene of predisposition to pinch-induced catalepsy. We investigated contribution of the fragment to regulation of sensitivity of catalepsy, sexual motivation and social investigation to classical tricyclic antidepressant imipramine. The sexual motivation was higher in AKR.CBA-D13Mit76 than in AKR mice. Chronic imipramine treatment (25 mg/kg) reduced it in AKR.CBA-D13Mit76 mice and had no effect on weakly expressed sexual motivation of AKR males. No significant effects of genotype or chronic imipramine treatment on characteristics of social interest were observed. Imipramine failed to alter catalepsy expression in AKR.CBA-DI3Mit76 mice. Possible molecular genetic mechanisms underlying difference in behavioral responses to antidepressant administration are discussed.     

Dual manifestation of catatonic reaction in rats

Results of genetic, neurophysiological, neurochemical and pharmacological suggest that the cataleptic freezing and "nervousness" observed in the cataleptic rat strain GC have a common mechanism. There seems to be a physiological factor causing catalepsy, upon reaching a certain level of intensity, to be transformed into "nervousness", which is observed both at different period and/or moment of individual life and in the processes of breeding the strain for predisposition to catalepsy.     

Effect of intranasal administration of dopamine on anxiety and locomotor activity of two lines of mice

Intranasal administration of dopamine (0.3; 3 and 30 microg/kg) on anxious behaviour of mice was studied using elevated plus-maze and open fields tests and the pinch-induced catalepsy on parallel bars test. Dopamine was introduced as nose drops or inhalation of nanoparticles of the compound solution in C57B1/6J and CBA/Lac mice with differences of dopaminergic function features. In our experiment, dopamine had anxiolytic and elevated motor activity effects in C57B1/6J, but not in the CBA/Lac mice. Nose drops were more effective than inhalation; perhaps, it was a more stressful manipulation. Apparently dopamine increased the number of CBA/Lac mice who demonstrated catalepsy and the reflex duration. Indeed, the neurotransmitter is active in different psycho-emotional phenomena.     

Anticataleptic effect of delta sleep-inducing peptide and its action on brain monoamine oxidase in rats genetically predisposed to catalepsy

Rats with genetic susceptibility to catalepsy (GC strain) were compared with Wistar rats (W). After an intraperitoneal administration of 120 micrograms/100 g delta sleep-inducing peptide (DSIP) in GC rats the duration of cataleptic freezing was shortened (13.8 +/- 9.5 sec against 27.2 +/- 7.5 sec in control). MAO-B activity decreased due to DSIP administration both in GC and W rats. It is hypothesized that the DSIP effect MAO-B in GC rats may correct the lost MAO-A function in deamination of dopamine, a common MAO-A and MAO-B substrate, and the dopaminergic neurotransmission in catalepsy.     

Genetic relationship of catalepsy to penduliform movements and audiogenic epilepsy in rats

Within outbred Wistar stock, the pendulum movements are found to be inherited in what may be considered as a dominant mono- or oligogenic mode of inheritance with incomplete penetrance. This indicates that the albinism only permits the manifestation of the pendulum movements, which are also controlled by some other gene or genes. The pendulum movements show a positive genetic relation to catalepsy, although this relation is not strong: the proportion of animals with pendulum movements is 23% in the control population and 32% in F12-F16 bred for catalepsy (p less than 0.05). Within the latter, the proportion of animals with pendulum movements was 43% in the progeny of parents with phenotypically expressed catalepsy, and 29% in the progeny of phenotypically "normal" animals (p less than 0.01). The frequency of audiogenic seizures was 32% in the control population and 17% in F8-F16 bred for catalepsy (p less than 0.001). A genetic model is proposed to account for the paradoxical situation, where pendulum movements have a positive genetic relation both to catalepsy and audiogenic epilepsy, the catalepsy being at the same time negatively related to epilepsy.     

Genetic control of catalepsy in mice

Pinch-induced immobility (catalepsy) was studied in mice of 9 inbred strains. CBA mice were found to be different from those of other strains both by the highest percent of cataleptics (56%) and by the highest duration of immobility. The Mendelian analysis of predisposition to catalepsy was performed on CBA and AKR mice strains contrasting in this feature. Reciprocal F1 hybrids did not display any catalepsy. Manifestation of cataleptics in the F2 and in CBA x F2 backcrosses suggested that catalepsy was inherited as a recessive, monogenic, autosomal feature.     

Catalepsy and "nervousness" in rats: results of replicated selection

Replicated breeding during five generations from an outbred population of Wistar rats performed, in contrast to the previous breeding, differentially for predisposition to catalepsy and "nervousness" confirmed earlier data that catalepsy and "nervousness" are two phenotypic expressions of the same bipolar catatonic genotype.     

Thermal interhemispheric asymmetry of the brain in rats in a cataleptic state]

The rat brain thermal fields were studied using the thermoencephaloscopic technique in three experimental conditions: the genetic catalepsy (GC rat strain), cataleptic phase of an audiogenic epileptic seizure (Krushinski?-Molodkina strain), and pharmacological catalepsy produced by haloperidol injection (Wistar rats). Irrespective of the experimental conditions, the state of catalepsy, accompanied by a decrease in the muscle tone and inhibition of motor reactions, was characterized by total asymmetric cooling of the brain cortex with the dominance of the right hemisphere. Temperature difference between the parieto-occipital areas of the right and left hemispheres reached 0.3-0.6 degree C.     

On “Pathomorphosis” of Cataleptic Response in Rats

Rats of the GC strain bred for predisposition to catalepsy show, apart from cataleptic “freezing, also an increased “nervousness.” An attempt to select from S₅₅ of the GC strain, on the one hand, expression of the “nervousness,” but, on the other hand, the lack of “nervousness” and duration of the cataleptic “freezing” led to differentiation of S₁ and S₂ off-springs of the bred groups for the “nervousness,” but not for expression of cataleptic reaction. Study of several behavioral and neurochemical characteristics revealed difference of the both bred groups from Wistar rats similar, this difference being of the same direction, but more pronounced in the “nervous” GC rat off-springs. The conclusion is made about the existence of the common mechanism of catalepsy and “nervousness,” while individual differences of these characteristics are accounted for by effects of conditional tropism or external (most likely, of early maternal) environment, with the latter affecting the “freezing” to the greater degree than the “nervousness.”     

Variation in the Correlation of G + C Composition with Synonymous Codon Usage Bias among Bacteria

G + C composition at the third codon position (GC3) is widely reported to be correlated with synonymous codon usage bias. However, no quantitative attempt has been made to compare the extent of this correlation among different genomes. Here, we applied Shannon entropy from information theory to measure the degree of GC3 bias and that of synonymous codon usage bias of each gene. The strength of the correlation of GC3 with synonymous codon usage bias, quantified by a correlation coefficient, varied widely among bacterial genomes, ranging from Open image in new window 0.07 to 0.95. Previous analyses suggesting that the relationship between GC3 and synonymous codon usage bias is independent of species are thus inconsistent with the more detailed analyses obtained here for individual species.     

Selection for the predisposition to catalepsy enhances depressive-like traits in mice

Immobility reaction or catalepsy is a natural passive defensive (lurking) behavioral response to the appearance of a predator. Selection for high predisposition to catalepsy has been performed in a population of (CBA x (CBA x AKR)) backcrosses of the crossing between mouse lines sensitive and resistant to catalepsy (VBA and AKR, respectively). A rapid increase in the number of animals with catalepsy has been observed: from 23% in backcrosses to 71% in the S3 generation. Selection for catalepsy does not affect mouse anxiety in the open field and plus-maze tests. However, S8 and S9 mice are characterized by a decreased motor activity in the open-field test and an increased immobility in the forced swim and tail suspension tests, which is interpreted as an increase in "depressiveness." The results indicate that genetically determined catalepsy is related to depressive-like characteristics of defensive behavior.     

Neurophysiology and analysis of the phenomenon of catalepsy

Neurophysiological mechanisms of the photogenic catalepsy (the "animal hypnosis"), genetic catalepsy, and cataplexy are discussed. The data obtained demonstrates a significance of the brainstem structures suppressing motor activity and the muscle tone in these conditions. Motor disorders associated with the general immobility are discussed from the standpoint of the evolutionary theory.