| Popis: |
only in rats developing learned helplessness. This cortical (5-HT) deficit can be prevented by prior training in escapable stress, by benzodiazepines, or subchronic tficyclic antidepressants 0~CA), via a GABAergic locus in M[~. Helplessness can also be reversed by cortical injection of TCA or of 5-l-IT. The hippocampus (IIPC) is also involved in LII with GABA both preventing and reversing LH and GABA blockade causing LH. Norepinephrine (NE) has a paradoxical effect in HPC, with NE release preventing LH but NE depletion correlating with LH. Septal 5-HT is key to LH reversal with TCA, and hypothalamus receives septohippocampal efferents with 5-HT and NE interactions hypothesized to mediate LI-I. Since LH is itself stressful, a maladaptive cycle is perpetuated, leading to subehronic behavioral deficits. Clinical predictions of the LH model will be discussed. |
