Effects of chronic bryostatin-1 on treatment-resistant depression in rats.

Despite over a half-century's intensive research worldwide, the currently available antidepressants remain sub-optimal. Therapeutic options for treatment-resistant depression, for instance, are rather limited. Here, we found that rats exhibited a lasting treatment-resistant depressive immobility in response to open space swim test at a high intensity of induction. The induced depressive behavior is associated with a dramatic impairment in spatial learning and memory. Both the depressive immobility and impairment in spatial learning and memory are sensitive to a period of chronic treatment with bryopstatin-1, a relatively selective activator of protein kinase Cε. Bryostatin-1-like analogues therefore might have therapeutic values for the treatment of treatment-resistant depression.