Increased amygdala and decreased hippocampus volume after schedule-induced polydipsia in high drinker compulsive rats.
Behav Brain Res
; 390: 112592, 2020 07 15.
Article
in En
| MEDLINE
| ID: mdl-32417273
ABSTRACT
Fronto-limbic structures and serotonin 2A receptors (5-HT2A) have been implicated in the pathophysiology and treatment of compulsive spectrum disorders. Schedule-Induced Polydipsia (SIP), characterized by the development of excessive drinking under intermittent food reinforcement schedules, is a valid preclinical model for studying the compulsive phenotype. In the present study, we explored the individual differences and effect of SIP in brain volume and 5-HT2A receptor binding in fronto-limbic structures in rats selected according to their compulsive drinking behavior. Rats were divided into high (HD) and low drinkers (LD) by SIP (20 sessions); later, we analyzed the brains of HD and LD selected rats, in two different conditions non-re-exposure (NRE) or re-exposure to SIP (RE), with four groups LD-NRE, LD-RE, HD-NRE and HD-RE. Histological analyses were carried out for volumetric (stereology) and receptor binding (autoradiography) in the prelimbic and infralimbic cortex, dorsal hippocampus and basolateral amygdala. After SIP re-exposure, HD-RE showed an increased basolateral amygdala and a reduced hippocampus volume compared to HD-NRE rats, and also compared to LD-RE rats. No differences were found between HD and LD in NRE condition. Moreover, HD rats exhibit a lower 5-HT2A receptor binding in the basolateral amygdala, independently of SIP re-exposure, compared to LD rats. However, LD-RE showed a decreased 5-HT2A receptor binding in basolateral amygdala compared to LD-NRE. No differences were found in the remaining structures. These findings suggest that SIP might be differentially impacting HD and LD brains, pointing towards a possible explanation of how the latent vulnerability to compulsivity is triggered.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Prefrontal Cortex
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Compulsive Behavior
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Receptor, Serotonin, 5-HT2A
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Drinking Behavior
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Polydipsia
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Basolateral Nuclear Complex
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Gyrus Cinguli
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Hippocampus
Limits:
Animals
Language:
En
Journal:
Behav Brain Res
Year:
2020
Document type:
Article
Affiliation country: