The effectiveness of extinction training in male rats: Temporal considerations and brain mechanisms.

The extinction of conditioned fear is frequently used in laboratories as a model for human exposure therapy and is crucial for studies of posttraumatic stress disorder (PTSD). However, the efficacy of specific protocols can vary greatly, and the underlying brain mechanisms are not sufficiently clarified. To address this issue, variable starting time (one or twenty-eight days after fear conditioning) and extinction protocols were used, and the efficacy and durability of fear extinction were also studied.

Monoacylglycerol lipase inhibition-induced changes in plasma corticosterone levels, anxiety and locomotor activity in male CD1 mice.

The hypothalamus-pituitary-adrenal-axis is strongly controlled by the endocannabinoid system. The specific impact of enhanced 2-arachidonoylglycerol signaling on corticosterone plasma levels, however, was not investigated so far. Here we studied the effects of the recently developed monoacylglycerol lipase inhibitor JZL184 on basal and stress-induced corticosterone levels in male CD1 mice, and found that this compound dramatically increased basal levels without affecting stress responses.

The effect of buspirone on normal and hypoarousal-driven abnormal aggression in rats.

Aggressiveness is associated with decreased glucocorticoid production, autonomic hypoarousal, and social deficits in antisocial personality disorder and its childhood antecedent conduct disorder. We showed previously that experimentally induced chronic glucocorticoid deficiency leads to abnormal forms of attack, autonomic hypoarousal, and social deficits in rats. We also showed that serotonergic neurotransmission, which downregulates aggressiveness in normal rats appears to lose its aggression-controlling role in glucocorticoid-deficient rats.

Social instability in female rats: effects on anxiety and buspirone efficacy.

Rationale: Buspirone produces inconsistent effects in laboratory rodents. Individual housing increases the efficacy of buspirone in male rats, suggesting that the effects of this (and other) compounds become conspicuous in animals showing anxiety-like states. The effect of individual housing was, however, weak, and evident only when the locomotor suppressive effects of buspirone dissipated (i.

Gender-specific effect of maternal deprivation on anxiety and corticotropin-releasing hormone mRNA expression in rats.

The long-term behavioral and neurochemical effects of 24h maternal separation were assessed in rats of both genders. Maternal deprivation was applied at the age of 9 days, whereas consequences were assessed 3 months later. Deprived rats (irrespective of gender) showed a considerable growth retardation that disappeared till adulthood.

Behavioral responses to social stress in noradrenaline transporter knockout mice: effects on social behavior and depression.

Noradrenaline has been implicated in the pathogenesis of depression and the noradrenaline transporter (NET) is a target for some antidepressants. Therefore, mice with disrupted NET gene expression (NET-KO) appear especially suitable for studying this behavioral disorder. We have examined the interaction between social stress (an etiological factor of depression) and the resulting depressive behaviors in NET-KO mice.