Biomedical subjects

G Laviola

Publications and source records attributed to G Laviola.

59 records · Page 4Linked to original sources

PubMed1986

Pretreatment of young mice with nerve growth factor enhances scopolamine-induced hyperactivity.

Twenty-one-day-old mice show a characteristic enhancement of locomotor activity upon injection of the cholinergic (muscarinic) blocking drug scopolamine. Intracerebral (third ventricle) injection of nerve growth factor (NGF) 24 h prior to scopolamine injection significantly enhances the drug-induced hyperactivity without modifying baseline activity. Such potentiation of the scopolamine effect was not obtained in 10-week-old mice treated and tested similarly.

Age Factors↗

PubMed1985

Short-, medium-, and long-term effects of prenatal oxazepam on neurobehavioural development of mice.

A benzodiazepine (oxazepam) was given to nulliparous mice on days 12-16 of pregnancy, and the development and young adult behaviour of the offspring were studied. Experiment 1, using 5, 15, and 50 mg/kg doses given PO twice daily, showed a dose-dependent retardation of postnatal development of several responses such as righting, bar holding, limb placing, and auditory startle. These changes were maximal in the first 2 postnatal weeks and then were markedly attenuated, or disappeared, being apparently related to a temporary retardation of body growth. A reduction of locomotor activity at 60 days was found only in the 50 mg/kg group. The effects of the 15 mg/kg dose on postnatal body growth and neurobehavioural development were replicated in Experiments 2 and 3. Moreover, in these experiments prenatal oxazepam reduced open field activity at 14-16 days and attenuated the hyperactivity induced by dl-amphetamine sulphate (2 mg/kg IP). On the other hand activity, habituation, and response to a scopolamine challenge (2 mg/kg IP) at 21-23 days were not significantly different from those of appropriate controls. Experiment 3, using a cross-fostering procedure, showed that postnatal maternal effects were not responsible for the changes so far mentioned. Experiment 2 also investigated the acquisition of several go-no go avoidance discriminations in a shuttle-box, using either light (L) or buzzer noise (N) as the "go" signal, a compound "no go" signal (NL in the L-"go" groups and LN in the N-"go" groups), and either an extinction or a passive avoidance contingency during the "no go" signal (4 weeks of training, starting at 60 days).(ABSTRACT TRUNCATED AT 250 WORDS)

Amphetamine↗

PubMedDate not supplied

Prenatal oxazepam enhances mouse maternal aggression in the offspring, without modifying acute chlordiazepoxide effects.

In the rat, behavioral changes during lactation are in several ways similar to those produced by benzodiazepines (BDZ). Moreover, an increased activity at the GABA/BDZ receptor complex has been found in both conditions. We tested the hypothesis that early manipulation of this neurochemical system by prenatal BDZ exposure should affect typical responses of lactating dams, such as maternal aggression. Outbred CD-1 mice were treated with either oxazepam (15 mg/kg PO twice/day on days 12-16 of fetal life) or vehicle and fostered at birth to untreated dams. Female offspring were subsequently mated at the young-adult stage and used to assess maternal aggressive responses towards a male intruder. In a first 5-min test on postpartum day 6, the prenatal oxazepam animals showed a reduced Latency to the First Attack, a markedly enhanced frequency of several offensive scores (such as Fighting Episodes, Attacks, and Offensive Upright, On Top, and Kicking Postures), a decrease of Submissive Postures and a reduced duration of time spent lying still (Out of the Nest). The tests were repeated 48 h later after IP treatment by either chlordiazepoxide (10 mg/kg) or saline. The drug significantly enhanced locomotor activity as well as the frequency of Fighting Episodes and of Attacks, while decreasing the number of Submissive Postures and the time spent On Nest. These effects were not significantly modified by prenatal oxazepam exposure. This suggests that long-term and acute effects of benzodiazepines are produced either by changes in different regulatory systems or by different types of changes in the same system.

Aggression↗

PubMedDate not supplied

Development of GABAergic modulation of mouse locomotor activity and pain sensitivity after prenatal benzodiazepine exposure.

Outbred CD-1 mice were exposed to oxazepam (15 mg/kg PO twice/day) on days 12-16 of fetal life, i.e., at a critical ontogenetic stage of Type II benzodiazepine (BDZ) receptor increase, and fostered at birth to untreated dams. Locomotor activity (single 30-min session in a Varimex apparatus), hot-plate responding, and muscimol (GABAa agonist) effects thereon [see normative data in (16)] were assessed on postnatal day 14, 21, or 28. Prenatal oxazepam did not affect the development of hot-plate responding and muscimol analgesia; however, it reduced activity on day 14 (as in previous studies) and modified the profile of muscimol effects at 21 days (time of first appearance of an adult-like pattern of activity) and at 28 days. Specifically, oxazepam mice showed a faster recovery from the initial depression after 1 mg/kg of muscimol at the former age and a lack of rebound hyperactivity at the latter age. These effects might be explained either 1) by an accelerated development of GABAergic regulatory mechanisms, or 2) by the same monoaminergic system changes which can account for other effects of prenatal BDZ exposure (1,3). In any event, the dissociation phenomena found in the present study strengthen the notion that GABAergic influences contribute to the modulation of locomotor activity and of pain reactivity by mechanisms which are at least in part separate from each other (16).

Analysis of Variance↗

PubMedDate not supplied

Prenatal oxazepam effects on cocaine conditioned place preference in developing mice.

The positively reinforcing and activity enhancing effects of IP cocaine (0, 5, or 25 mg/kg) were assessed at three ages (14-17, 21-24, and 28-31 days) in outbred CD-1 mouse pups treated prenatally by either oxazepam (OX, 15 mg/kg PO twice/day on days 12-16 of pregnancy) or vehicle (VEH). A 4-day unbiased conditioned place preference (CPP) procedure was used with combined visual and tactile cues (white walls and wide-mesh metal floor versus black walls and narrow-mesh floor). A single 25 mg/kg cocaine dose produced CPP in both prenatal groups of 28-31 day-old mice. At the two younger ages, a significant cocaine CPP was found in prenatal OX mice but not in vehicle animals; the latter apparently developed CPP less readily than the offspring of indisturbed dams in a previous experiment. On the other hand, prenatal OX did not produce substantial changes in the developmental profile of cocaine effects on locomotor activity, consisting of a dose-related response enhancement which is much more marked at 22 and 29 days than before weaning.

Aging↗