Related Experiment Video
Updated: Jun 10, 2026
Social Defeat Stress Model for Adolescent C57BL/6 Male and Female Mice
Published on: March 15, 2024
Juvenile stress attenuates the dorsal hippocampal postsynaptic 5-HT1A receptor function in adult rats
Hirokazu Matsuzaki1, Takeshi Izumi, Takahiro Horinouchi
1Department of Neuropharmacology, Hokkaido University Graduate School of Medicine, North 15, West 7, Sapporo, 060, Japan.
Rationale:
Traumatic events in early life are associated with an increased risk of psychiatric diseases in adulthood. 5-hydroxytryptamine (5-HT)(1A) receptors play a pivotal role in the 5-HTergic mechanisms associated with the etiology of stress-related disorders.
Objective:
The goal of the present study was to investigate whether juvenile stress influences emotional control via postsynaptic 5-HT(1A) receptor in the hippocampus and amygdala using contextual fear conditioning test in adult rats.
Methods:
The rats were subjected to aversive footshock (FS) during the third week of the postnatal period (3wFS group). During the postadolescent period (10-14 weeks postnatal), experiments were performed.
Results:
The systemic administration of the 5-HT(1A) receptor agonist R-(+)-8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) (0.2 mg/kg, i.p.) attenuated the freezing behavior in the non-FS group, but not in the 3wFS group. The bilateral local injection of 8-OH-DPAT (1 μg/side) into the amygdala decreased the freezing behavior in the non-FS group and the 3wFS group. However, the local injection of 8-OH-DPAT (1 μg/side) into the hippocampus decreased the freezing behavior in the non-FS group, but not in the 3wFS group. In a 5-HT(1A) receptor binding study, the Bmax of the 3wFS group decreased in the dorsal hippocampus, but not the amygdala in comparison with the non-FS group.
Conclusions:
The juvenile stress attenuated the hippocampal postsynaptic 5-HT(1A) receptor function in context-dependent conditioned fear.
