Cannabinoid functions in the amygdala contribute to conditioned fear memory in streptozotocin-induced diabetic mice: interaction with glutamatergic functions.

Cannabinoid functions in the amygdala contribute to conditioned fear memory in streptozotocin-induced diabetic mice: interaction with glutamatergic functions.
Exp Neurol. 2015 Apr 27;
Authors: Ikeda H, Ikegami M, Kai M, Kamei J
Abstract
The role of cannabinoid systems in conditioned fear memory was investigated in streptozotocin (STZ)-induced diabetic mice. The cannabinoid receptor agonist WIN-55,212-2 (1 mg/kg, i.p.), when injected into normal mice after conditioning, significantly prolonged the duration of freezing behavior. This effect was significantly inhibited by the cannabinoid CB1 receptor antagonist AM 251 (3 mg/kg, s.c.), but not by the cannabinoid CB2 receptor antagonist AM 630 (1 mg/kg, s.c.). The duration of freezing in STZ-induced diabetic mice was significantly longer than that in non-diabetic mice. The injection of WIN-55,212-2 (1 mg/kg, i.p.) after conditioning significantly prolonged the duration of freezing in non-diabetic mice, but not in STZ-induced diabetic mice. In contrast, the injection of AM 251 (3 mg/kg, s.c.) after conditioning significantly shortened the duration of freezing in STZ-induced diabetic mice, but not in non-diabetic mice. The injection of AM 251 (3 mg/kg, s.c.) before conditioning or before testing did not significantly affect the duration of freezing in STZ-induced diabetic mice. The protein levels of cannabinoid CB1 receptors in the amygdala were increased in STZ-induced diabetic mice. In co...

Source: Experimental Neurology - April 27, 2015 Category: Neurology Authors: Ikeda H, Ikegami M, Kai M, Kamei J Tags: Exp Neurol Source Type: research