Lack of effects of 5HT3 receptor antagonists in the social interaction and elevated plus-maze tests of anxiety in the rat

Attachment insecurity in the forms of attachment anxiety and avoidance is associated with mental disorders in humans. In this research field, rodents, especially mice and rats, are commonly used to study social behaviors and underlying biological mechanisms due to their pronounced sociability. However, quantitative assessment of attachment security/insecurity in rodents has been a major challenge. The present study identified attachment insecurity behaviors in rats subjected to maternal separation (MS) during postnatal days (PD) 2–16 and early weaning (EW) during PD 17–21. This MSEW procedure has been used to mimic early life neglect in humans. After MSEW, rats continued to survive until early adulthood when they were subjected to open-field, social interaction, and elevated-plus maze tests. Compared to CNT rats in either gender, MSEW rats moved longer distances at higher velocities in the open-field. The MSEW rats also showed lower ratios of travel distance at central zone over that on whole arena of the open-field compared to CNT rats. In social interaction test, male CNT rats preferred to investigate an empty cage than females; whereas female CNT rats spent more time with a partner-containing cage as compared to males. This gender-specific difference was reversed in MSEW rats. On elevated-plus maze female CNT rats exhibited more risk-taking behaviors as compared to male counterparts. Moreover, female MSEW rats experienced a greater difficulty in making a decision on whether approaching to or averting from which arms of elevated-plus maze. Taken together, male MSEW rats behaved like attachment anxiety while females’ phenotype is alike to attachment avoidance described in humans. These results shall prompt further application of MSEW rat in abnormal psychology and biological psychiatry research.

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Increasing 3α,5α-THP following inhibition of neurosteroid biosynthesis in the ventral tegmental area reinstates anti-anxiety, social, and sexual behavior of naturally receptive rats

Reproduction ◽

10.1530/rep-08-0250 ◽

2009 ◽

Vol 137 (1) ◽

pp. 119-128 ◽

Cited By ~ 23

Author(s):

Cheryl A Frye ◽

Jason J Paris ◽

Madeline E Rhodes

Keyword(s):

Sexual Behavior ◽

Social Interaction ◽

Ventral Tegmental Area ◽

Mating Behavior ◽

Elevated Plus Maze ◽

Female Rats ◽

Plus Maze ◽

Ventral Tegmental ◽

Behavior Inhibition ◽

Progesterone Metabolite

The progesterone metabolite and neurosteroid, 5α-pregnan-3α-ol-20-one (3α,5α-THP), has actions in the midbrain ventral tegmental area (VTA) to modulate lordosis, but its effects on other reproductively relevant behaviors are not well understood. Effects on exploration, anxiety, and social behavior resulting from inhibition of 3α,5α-THP formation, as well as 3α,5α-THP enhancement, were investigated in the midbrain VTA. Naturally sexually receptive, female rats (n=8–10/group) received infusions aimed at the midbrain VTA of vehicle, PK11195 (an inhibitor of neurosteroidogenesis), and/or indomethacin (an inhibitor of 3α,5α-THP formation from prohormones), and were subsequently infused with vehicle or FGIN 1-27 (a neurosteroidogenesis enhancer). The rats were then assessed in a behavioral battery that examined exploration (open field), anxiety (elevated plus maze), social (social interaction), and sexual (paced mating) behavior. Inhibition of 3α,5α-THP formation decreased exploratory, anti-anxiety, social, and sexual behavior, as well as midbrain 3α,5α-THP levels. Infusions of FGIN 1-27 following 3α,5α-THP inhibition restored these behaviors and midbrain 3α,5α-THP levels to those commensurate with control rats that had not been administered inhibitors. These findings suggest that 3α,5α-THP formation in the midbrain VTA may influence appetitive, as well as consummatory, aspects of mating behavior.

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Excitotoxic lesions of the medial prefrontal cortex attenuate fear responses in the elevated-plus maze, social interaction and shock probe burying tests

Brain Research ◽

10.1016/s0006-8993(03)02299-6 ◽

2003 ◽

Vol 969 (1-2) ◽

pp. 183-194 ◽

Cited By ~ 124

Author(s):

Akeel A Shah ◽

Dallas Treit

Keyword(s):

Prefrontal Cortex ◽

Social Interaction ◽

Medial Prefrontal Cortex ◽

Elevated Plus Maze ◽

Plus Maze

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Tianeptine counteracts the anxiogenic effects of benzodiazepine withdrawal, but not those of exposure to cat odour

European Psychiatry ◽

10.1017/s0924933800005423 ◽

1993 ◽

Vol 8 (S2) ◽

pp. 75s-80s

Author(s):

SE File ◽

N Andrews ◽

H Zangrossi

Keyword(s):

Social Interaction ◽

Acute Administration ◽

Social Interaction Test ◽

Anxiety States ◽

Plus Maze ◽

The Social ◽

5 Ht Uptake ◽

Benzodiazepine Withdrawal ◽

Chronic Diazepam ◽

Interaction Test

SummaryTianeptine is a clinically effective anti-depressant with the unusual profile of increasing 5-HT uptake, thereby decreasing the synaptic availability of 5-HT. In the social interaction test of anxiety in the rat, withdrawal from chronic diazepam treatment produced a significant anxiogenic response that was reversed by acute administration of tianeptine (2.5–10 mg/kg). These doses were without significant effect in the vehicle-treated rats. Exposure of rats to cat odour resulted in anxiogenic responses in the plus-maze and social interaction tests and in decreased exploration. These changes were not reversed by 5 days treatment with tianeptine (2.5–10 mg/kg). Thus, tianeptine may not he effective in all anxiety states, but could be particularly useful in treating patients withdrawn from benzodiazepines.

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