Neuroscience and Neurobiology Commons^™

Computer Vision Evidence Supporting Craniometric Alignment Of Rat Brain Atlases To Streamline Expert-Guided, First-Order Migration Of Hypothalamic Spatial Datasets Related To Behavioral Control, Arshad M. Khan, Jose G. Perez, Claire E. Wells, Olac Fuentes

Arshad M. Khan, Ph.D.

Insular Cortex Lesions And Morphine-Induced Suppression Of Conditioned Stimulus Intake In The Rat, Christopher T. Roman, Steve Reilly

Christopher Roman

The present experiment examined the influence of insular cortex (IC) lesions on the intake of a taste stimulus in a consummatory procedure that used morphine as the unconditioned stimulus. In normal rats, morphine caused a rapid reduction in saccharin intake when the taste was novel but not when it was familiar. Irrespective of stimulus novelty, morphine had little influence on the saccharin consumption of IC-lesioned rats. The results are discussed in terms of a lesion-induced disruption of (i) a reward comparison mechanism and (ii) the perception of taste novelty.

Taste, Olfactory And Trigeminal Neophobia In Rats With Forebrain Lesions, Jian-You Lin, Christopher T. Roman, Justin St. Andre, Steve Reilly

Christopher Roman

The present study was designed to examine whether lesions of the insular cortex (IC; Experiment 1), the basolateral amygdala (BLA) or medial amygdala (MeA; Experiment 2) influence the neophobic reactions to orally consumed liquid stimuli. Three different types of stimuli were used: taste (0.5% saccharin), olfactory (0.1% amyl acetate), and trigeminal (0.01 mM capsaicin). Rats with IC, BLA and MeA lesions showed normal responses to the olfactory and trigeminal stimuli. Each type of lesion, however, disrupted the initial occurrence of neophobia to the taste stimulus. The significance of these findings to conditioned taste aversion is discussed.

Taste-Potentiated Odor Aversion Learning In Rats With Lesions Of The Insular Cortex, Jian-You Lin, Christopher T. Roman, Steve Reilly

Christopher Roman

The current study assessed the influence of excitotoxic lesions of the insular cortex (IC) on tastepotentiated odor aversion (TPOA) learning. Water-deprived rats initially received a single odortoxicosis or odor/taste-toxicosis pairing and were subsequently tested, in separate trials, with the odor and the taste stimulus. Indicating TPOA, neurologically intact rats conditioned with the odor/taste compound stimulus acquired significantly stronger odor aversions than normal rats conditioned with the odor stimulus. IC lesions disrupted TPOA, conditioned taste aversion and taste neophobia. The finding that taste did not potentiate odor aversion learning in the IC lesioned rats provides support for the “within-compound association” analysis …

Taste Neophobia And C-Fos Expression In The Rat Brain, Jian-You Lin, Christopher T. Roman, Joe Arthurs, Steve Reilly

Christopher Roman

Taste neophobia refers to a reduction in consumption of a novel taste relative to when it is familiar. To gain more understanding of the neural basis of this phenomenon, the current study examined whether a novel taste (0.5% saccharin) supports a different pattern of c-Fos expression than the same taste when it is familiar. Results revealed that the taste of the novel saccharin solution evoked more Fos immunoreactivity than the familiar taste of saccharin in the basolateral region of the amygdala, central nucleus of the amygdala, gustatory portion of the thalamus, and the gustatory insular cortex. No such differential expression …

Effects Of Insular Cortex Lesions On Conditioned Taste Aversion And Latent Inhibition In The Rat, Christopher T. Roman, Steve Reilly

Christopher Roman

The present study tested the hypothesis that lesions of the insular cortex of the rat retard the acquisition of conditioned taste aversions (CTAs) because of an impairment in the detection of the novelty of taste stimuli. Demonstrating the expected latent inhibition effect, nonlesioned control subjects acquired CTAs more rapidly when the conditioned stimulus (0.15% sodium saccharin) was novel rather than familiar (achieved by pre-exposure to the to-be-conditioned taste cue). However, rats with insular cortex lesions acquired taste aversions at the same slow rate regardless of whether the saccharin was novel or familiar. The pattern of behavioural deficits obtained cannot be …

Morphine-Induced Suppression Of Conditioned Stimulus Intake: Effects Of Stimulus Type And Insular Cortex Lesions, Jian-You Lin, Christopher T. Roman, Steve Reilly

Christopher Roman

Intake of an unconditionally preferred taste stimulus (e.g., saccharin) is reduced by contingent administration of a drug of abuse (e.g., morphine). We examined the influence of insular cortex (IC) lesions on morphine-induced suppression of an olfactory cue and two taste stimuli with different levels of perceived innate reward value. Two major findings emerged from this study. First, morphine suppressed intake of an aqueous odor as well as each taste stimulus in neurologically intact rats. Second, IC lesions disrupted morphine-induced suppression of the taste stimuli but not the aqueous odor cue. These results indicate that the perceived innate reward value of …

Basolateral Amygdala And Morphine-Induced Taste Avoidance In The Rat, Jamie Lovaglio, Jian-You Lin, Christopher T. Roman, Steve Reilly

Christopher Roman

The present experiment examined the influence of excitotoxic lesions of the basolateral amygdala (BLA) on morphine-induced saccharin avoidance. Neurologically intact subjects rapidly learned to avoid drinking the taste conditioned stimulus (CS), an effect that was sustained throughout the experiment. Although the BLA-lesioned (BLAX) rats showed CS avoidance over the first few trials, the effect was not sustained. That is, by the end of the experiment, the BLAX rats were drinking the same amount of saccharin after seven saccharin-morphine trials as they did on the first trial (i.e., prior to the morphine injections). Potential interpretations of the results are discussed including …

Conditioned Taste Aversion And Latent Inhibition Following Extensive Taste Preexposure In Rats With Insular Cortex Lesions, Christopher T. Roman, Jian-You Lin, Steve Reilly

Christopher Roman

Lesions of the insular cortex (IC) attenuate acquisition of conditioned taste aversions (CTAs). We have suggested that this impairment is the expected consequence of a failure of IC-lesioned (ICX) rats to recognize unfamiliar taste stimuli as novel. That is, ICX rats treat novel taste stimuli as if they are familiar and as a result show a latent inhibition-like retardation of learning. This account anticipates that ICX rats should acquire CTAs at the same slow rate as normal rats that are familiar with the taste stimulus. The present experiment confirmed this hypothesis in a design that compared CTA acquisition in normal …

Radial-Maze Performance In The Rat Following Lesions Of Posterior Neocortex, Melvyn A. Goodale, Robert H.I. Dale

Robert H. I. Dale

The present experiment was designed to investigate the role of posterior neocortex (areas 17, 18 and 18a) in the maintenance of performance on the radial maze. Following training to criterion on the 8-arm radial maze, rats received either sham operations, bilateral eye enucleations, lesions of posterior neocortex, or combined enucleations and lesions of posterior neocortex. While the enucleated animals with intact brains showed a slight, but significant performance decrement relative to the sham-operated group, the other two groups, with lesions of areas 17, 18 and 18a, each showed a massive deficit. This large deficit was observed even in the group …

Parallel-Arm Maze Performance Of Sighted And Blind Rats: Spatial Memory And Maze Structure, Robert H.I. Dale

Robert H. I. Dale

Sighted and peripherally blinded groups of rats learned to obtain a small reward from each arm of an eight-arm parallel maze, and a sighted group was similarly trained on a radial maze. The parallel-sighted and parallel-blind groups were equally slow, and much slower than the radial-sighted group, to attain criterion performance. The three groups shared several response characteristics: selectively avoiding the most recently entered arms, frequently choosing adjacent arms, and an absence of 'spatial generalization' among the arms. The findings support a simple model proposing how subjects identify and choose among the maze-arms.

Perinatal Exposure To Polychlorinated Biphenyls Alters Social Behaviors In Rats, Howard C. Cromwell

Howard Casey Cromwell

Perinatal exposure to polychlorinated biphenyls (PCBs) leads to significant alterations of neural and hormonal systems. These alterations have been shown to impair motor and sensory development. Less is known about the influence of PCB exposure on developing emotional and motivational systems involved in social interactions and social learning. The present study examined the impact of perinatal PCB exposure (mixture of congeners 47 and 77) on social recognition in juvenile animals, conspecific-directed investigation in adults and on neural and hormonal systems involved in social functions. We used a standard habituation–dishabituation paradigm to evaluate juvenile recognition and a social port paradigm to …

Pathological Alterations In Gabaergic Interneurons And Reduced Tonic Inhibition In The Basolateral Amygdala During Epileptogenesis, Michael A. Rogawski, Brita Fritsch, Felicia Qashu, T. H. Figueiredo, Vicki Aroniadou-Anderjaska, Maria F.M. Braga

Michael A. Rogawski

An acute brain insult such as traumatic head/brain injury, stroke, or an episode of status epilepticus can trigger epileptogenesis, which, after a latent, seizure-free period, leads to epilepsy. The discovery of effective pharmacological interventions that can prevent the development of epilepsy requires knowledge of the alterations that occur during epileptogenesis in brain regions that play a central role in the induction and expression of epilepsy. In the present study, we investigated pathological alterations in GABAergic interneurons in the rat basolateral amygdala (BLA), and the functional impact of these alterations on inhibitory synaptic transmission, on days 7 to 10 after status …