The involvement of arginine vasotocin in the maturation of the kitten brain

The influence of oxytocin-based interventions on sleep-wake and sleep-related behaviour and neurobiology: A systematic review of preclinical and clinical studies

The oxytocin (OXT) system has garnered considerable interest due to its influence on diverse behaviours. However, scant research has considered the influence of oxytocin on sleep-wake and sleep-related behaviour and neurobiology. Consequently, the objective of this systematic review was to assess the extant preclinical and clinical evidence for the influence of oxytocin-based interventions on sleep-wake outcomes. The primary search was conducted on 22/7/2020 using six electronic databases; 30 studies (19 preclinical, 11 clinical) were included based on inclusion criteria. Studies were evaluated for risk of bias using the SYRCLE tool and the Cochrane risk of bias tools for preclinical and clinical studies, respectively. Results indicated manipulation of the OXT system can influence sleep-wake outcomes. Preclinical evidence suggests a wake-promoting influence of OXT system activation whereas the clinical evidence suggests little or no sleep-promoting influence of OXT. OXT dose was identified as a likely modulatory factor of OXT-induced effects on sleep-wake behaviour. Future studies are necessary to validate and strengthen these tentative conclusions about the influence of OXT on sleep-wake behaviour.

Effects of peptides on animal and human behavior: a review of studies published in the first twenty years of the journal Peptides

This review catalogs effects of peptides on various aspects of animal and human behavior as published in the journal Peptides in its first twenty years. Topics covered include: activity levels, addiction behavior, ingestive behaviors, learning and memory-based behaviors, nociceptive behaviors, social and sexual behavior, and stereotyped and other behaviors. There are separate tables for these behaviors and a short introduction for each section.

Postnatal administration of two peptide solutions affects passive avoidance behaviour of young rats

The effects of two subcutaneously injected peptide solutions CERE (100 mg/kg b. wt.) and E021 (1 mg/kg b. wt.) and of 0.9% saline on passive avoidance reaction (PAR) of young rats were examined. Animals were trained and tested in a step-through avoidance task using a footshock of 0.5 mA or 1 mA. Step-through latencies were observed up to 200 s and from these data the percentage of good learners (latency = 200 s) and bad learners (latency < 200 s) was calculated. Two experimental schedules were performed (n > 6). In Expt. 1 rat pups were chronically treated with the substances within the first 7 days after birth. In Expt. 2 the 7 days of treatment started in the 4th postnatal week. In both experiments PAR acquisition was trained on the 28th day after birth (learning trial), PAR extinction testing started on the 29th day (retention trials). After applying a 0.5-mA footshock, rat pups treated with E021 within the first 7 days of life (Expt. 1) displayed significantly slower PAR extinction when compared to saline- and CERE-treated rats. In the 1 mA groups, significant differences in step-through latencies were measured between 0.9% saline- and E021-pretreated animals on retention day 11 and between saline and CERE on retention days 9 and 13. E021-treated rats of Expt. 2, receiving a footshock intensity of 0.5 mA, showed significant lower step-through latencies when compared to E021-treated rats of Expt. 1. In Expt. 2 no significant differences between treatment groups were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Vasotocin increases quiet sleep and suppresses active sleep in newborn cats. Opposite effects after vasotocin immunoneutralization

One picogram of synthetic arginine vasotocin (AVT) administered into the lateral ventricle of newborn cats aged 7-9 days, increased the amount of quiet sleep and markedly decreased the amount of active sleep. Ten pg AVT completely suppressed active sleep during the recording time of 3 hr. The increase in the quiet sleep occurred within 5-7 min and lasted for the entire recording time of 3 hr. An undiluted specific AVT antiserum (10 microliters) administered into the lateral ventricle, induced opposite effects suppressing quiet sleep and increasing active sleep. It is concluded that in newborn cats both AVT and the AVT antiserum induce the same hypnogenic effects as in the adult cats.

Vasotocin improves intelligence and attention in mentally retarded children

In mentally retarded (MR) prepubertal children, investigated both before and after six months of treatment, synthetic arginine vasotocin (AVT) (10(-6) mg/day/0.1 ml, intranasally), but not oxytocin or saline alone, significantly increased the intelligence quotient (IQ) and improved the attention parameters without affecting the short-term memory. Taking into account both the psychometric results and the clinical observations, the effects of AVT could be mainly explained by assuming the improvement of attention. Since there was a significant inverse correlation between the pretreatment levels of the IQ and attention scores and their increase after AVT, and since the AVT effects tend to be more intense in autistic children, we hypothesize that the more affected the attention mechanisms, the more they are sensitive to AVT. The present results are tentatively explained by the paradoxical sleep-enhancing properties of AVT, mechanisms by which AVT could improve the brain plasticity in MR subjects and by this, the attention performance.

Effect of peripheral administration of arginine vasotocin on neonatal sleep in rats

Vasotocin was recently reported to increase the neonatal amount of active sleep in kittens. In this study we examined the effects of arginine vasotocin (vasotocin), given intraperitoneally and at a wide dose range, on the sleep-wake behavior of 7-day-old and 14-day-old rat pups using a static charge sensitive recording system. It increased the percentage of quiet state relative to total sleep time at the doses of 0.01-1.0 ng/g of body weight but did not affect it at the dose of 0.001 ng/g. The percentage of active sleep was decreased by doses of 0.01-10.0 ng/g. The increase in the amount of quiet state and the concurrent suppression of active sleep lasted for 6 hours. Wakefulness was slightly increased at 10 ng/g of vasotocin. These findings indicate that, in contrast to the reports on kittens, in newborn rats peripheral administration of vasotocin increases the amount of quiet state relative to total sleep time and decreases that of active sleep.

Opposite effects of vasotocin and of a specific vasotocin antiserum on active sleep of kittens

The effects of intracerebroventricularly administered synthetic arginine vasotocin (AVT) or undiluted AVT, vasopressin (AVP) and oxytocin (OT) antisera on active sleep (AS) of newborn kittens have been investigated in comparison with rabbit serum control. In contrast to AVP and OT antisera, AVT antiserum has produced opposite effects on AS as AVT itself. Since after 10 microliter of undiluted AVT antiserum the percentage of AS did not decrease under 20% and even after 100 microliter AS did not decrease under 5%, it is concluded that, at least during perinatal life, AVT could be considered as a neuromodulator with AS-promoting effect.

Central nervous system effects of peptides, 1980-1985: a cross-listing of peptides and their central actions from the first six years of the journal Peptides

A tabular synopsis is presented for articles concerned with the effects of peptides on the central nervous system that appeared in the journal Peptides from 1980-1985. A table arranged alphabetically by peptide and one arranged by effects, both listing routes of injection, species, direction of change, and qualifying notes, provides easy cross-referencing of peptides and their effects. Over 80 peptides and over 135 effects are listed. The list of peptides includes, but is not limited to: ACTH, angiotensin, bombesin, bradykinin, calcitonin, casomorphin, CCK, ceruletide, CGRP, CRF, dermorphin, DSIP, dynorphin, endorphins, enkephalins, GRF, gastrin, LHRH, litorin, metkephamid, MIF-l, motilin, MSH, NPY, NT, oxytocin, ranatensin, sauvagine, substances P and K, somatostatin, TRH, VIP, vasopressin, and vasotocin. The list of effects includes, but is not limited to: aggression, alcohol, analgesia, attention, avoidance, behavior, cardiovascular regulation, catalepsy, conditioned behavior, convulsions, dopamine binding and metabolism, discrimination, drinking, EEG, exploration, feeding, fever, gastric secretion, GI motility, grooming, learning, locomotor behavior, mating, memory, neuronal activity, open field, operant behavior, rearing, respiration, satiety, scratching, seizure, sleep, stereotypy, temperature, thermoregulation and tolerance.

Pharmacological evidence that effects of vasotocin on brain maturation are mediated by GABA mechanisms

Active sleep, brain weight as well as total lipids and galactolipids were assayed in 8-day-old rat pups, after daily administration (between 2 and 8 days of postnatal age) of saline, arginine vasotocin (AVT) (10(-7) mg), picrotoxin (5 x 10(-5) mg), valproic acid (10(-5) and 10(-6) mg) or of AVT + picrotoxin and AVT + valproic acid. AVT increases active sleep and decreases the weight, total lipids and the galactolipids of the brain. Although picrotoxin alone was without any apparent effects on maturational parameters, when administered together with AVT, it completely prevented AVT from producing its effects. Valproic acid had AVT-like effects when administered in a higher dose (10(-5) mg), but was without any apparent effects when administered in the lower dose (10(-6) mg). However, both doses intensely potentiated the effects of AVT. Since both drugs specifically interfere with the GABAergic neurotransmission, it is concluded that AVT retards the accumulation of brain lipids by activating a GABAergic pathway.

Body and brain growth following continuous perinatal administration of arginine- and lysine-vasopressin to the homozygous Brattleboro rat

Using a recently developed controlled-drug-delivery implantation technique, arginine-vasopressin (AVP) or lysine-vasopressin (LVP) was administered to homozygous (HOM) Brattleboro rats throughout pregnancy in order to study the influence of compensation for the deficiency of AVP on body and brain development in their HOM offspring. This mutant is retarded in both body and brain growth from the neonatal period onwards. In one subgroup the LVP-treatment was continued postnatally by means of subcutaneous implantation in the pups. AVP treatment had no growth-stimulating effect either on pup body weight at day one or on postnatal body growth, nor did it affect noticeably the day of eye opening, or a number of brain parameters measured at one month of age. LVP treatment, in contrast, resulted in higher body weights at birth, which could be maintained postnatally if the pups were reared with a Wistar foster-mother. At one month of age body as well as brain weights were still larger in the treated pups. Although cerebellar weight was larger than in untreated Brattleboro pups in this group, cerebellar DNA content or gross morphology, known to be impaired in HOM rats, were not changed. LVP treatment of the pups, as well as maternal AVP-treatment beginning on day 15 of pregnancy, had inhibiting rather than growth-stimulating effects, high-lighting the different effects created by these two peptides at different stages of development.

The pineal gland: anatomy, physiology, and clinical significance

Since the discovery of melatonin approximately 25 years ago, there has been intense study regarding the details of the structure and function of the pineal gland. This work is reviewed, with particular emphasis on those aspects of importance to human physiology and disease.

Neuropeptide effects on brain development to be expected from behavioral teratology

A wealth of literature has become available about lasting functional consequences of perinatal psychotropic drug exposure, having affected brain development in a subtle rather than gross structural way (behavioral teratology or functional neuroteratology). The underlying mechanism is thought to result from changing levels of neurotransmitters during neurogenesis induced by these neuroactive drugs, which as a consequence appears to lead to impaired cell acquisition and receptor setting i.e., to irreversible changes in particular neuronal circuitries. Neuropeptides are true candidates for a neurotransmission function as well, and are also present early in brain development. As for the classical neurotransmitters, a role for neuropeptides in the growth and functional organization of the nervous system, might therefore be expected. Anomalies in neuropeptide levels also would lead to functional neuroteratology. Although not overwhelming, several studies support this view, and the current state is summarized in this paper: a trophic role for some neuropeptides as well as neuroteratological effects upon perinatal manipulation for others were revealed. However, more detailed studies are necessary, certainly also because of the crying need for exposing possible adverse effects at a time when clinical applications of neuropeptides and their analogues are becoming a mode.