Chronic nicotine exposure attenuates the effects of Δ -tetrahydrocannabinol on anxiety-related behavior and social interaction in adult male and female rats.

Introduction: Anxiogenic and anxiolytic effects of cannabinoids are mediated by different mechanisms, including neural signaling via cannabinoid receptors (CBRs) and nicotinic cholinergic receptors (nAChRs). This study examined the effects of prior nicotine (the psychoactive component in tobacco) exposure on behavioral sensitivity to delta-9-tetrahydrocannabinol (THC; the psychoactive component of cannabis) challenge in animals.

Methods: Male and female adult Sprague-Dawley rats (N = 96) were injected daily with nicotine (1 mg/kg, i.

Maternal immune activation produces cerebellar hyperplasia and alterations in motor and social behaviors in male and female mice.

There have been suggestions that maternal immune activation is associated with alterations in motor behavior in offspring. To explore this further, we treated pregnant mice with polyinosinic:polycytidylic acid (poly(I:C)), a viral mimetic that activates the innate immune system, or saline on embryonic days 13-15. At postnatal day (P) 18, offspring cerebella were collected from perfused brains and immunostained as whole-mounts for zebrin II.

Effect of complete maternal and littermate deprivation on morphine-induced Fos-immunoreactivity in the adult male rat brain.

Previous research has demonstrated that rats reared in isolation from their dam and littermates show altered behavioral responsiveness to both natural and drug-mediated rewards. This study examined the effects of complete maternal deprivation through the use of artificial rearing on neural activation after acute morphine exposure in adulthood. Male rats were either artificially reared (AR) or maternally reared (MR) from postnatal day 5 to 21.

Conditioned nausea in rats: assessment by conditioned disgust reactions, rather than conditioned taste avoidance.

The terms conditioned taste avoidance and conditioned taste aversion are often used interchangeably in the literature; however, considerable evidence indicates that they may represent different processes. Conditioned taste avoidance is measured by the amount that a rat drinks in a consumption test that includes both appetitive phases and consummatory phases of responding. However, conditioned taste aversion is more directly assessed using the taste reactivity (TR) test that includes only the consummatory phase of responding.

Differential effects of neurotoxin-induced lesions of the basolateral amygdala and central nucleus of the amygdala on lithium-induced conditioned disgust reactions and conditioned taste avoidance.

When rats are intraorally exposed to saccharin solution that has previously been paired with lithium chloride (LiCl), they display Pavlovian conditioned disgust reactions. When exposed to LiCl-paired saccharin solution by bottle, they display suppressed instrumental approach to the bottle resulting in suppressed consumption. The present experiments demonstrated that while neither neurotoxin-induced lesions of the basolateral amygdala (BLA) nor the central nucleus of the amygdala (CeA) attenuated the display of Pavlovian conditioned disgust reactions, lesions of the BLA (but not the CeA) attenuated instrumental conditioned avoidance of the taste.

Effect of prior exposure to a lithium- and an amphetamine-paired flavor on the acoustic startle response in rats.

The experiments reported here evaluated the hypothesis that an amphetamine-paired flavor elicits conditioned fear-arousal, whereas a lithium-paired flavor elicits conditioned nausea-disgust by examining the effect of prior flavor exposure on an acoustic startle reaction (ASR). Exposure to a lithium-paired flavor by intraoral infusion, either immediately prior to a startle session (Experiment 1) or during a startle session (Experiments 2 and 3), resulted in a blunted ASR. In contrast, intraoral infusion of an amphetamine-paired flavor resulted in a potentiated ASR.

Extinction of a saccharin-lithium association: assessment by consumption and taste reactivity.

Extinction of a conditioned palatability shift preceded extinction of conditioned taste avoidance whether rats were tested using a within-subjects design or a between-subjects design. In each of two experiments, consumption of 0.1% saccharin was paired with either 20 ml/kg of 0.

Artificial rearing alters the response of rats to natural and drug-mediated rewards.

Artificial rearing (AR) of infant rats permits precise control over key features of the early environment without maternal influence. The present study examined the behavioral response of AR rats towards natural and drug-mediated rewards, as well as their exploratory and affective behaviors. Adolescent AR rats showed increased preference for sucrose consumption relative to chow and demonstrated greater activity in the open field and in the elevated plus-maze compared to maternally reared (MR) rats.