Antidepressants reverse the inhibition of shock-induced aggression elicited by a prior inescapable shock

Considerations on nonclinical approaches to modeling risk factors of suicidal ideation and behavior

Given the serious nature of suicidal ideation and behavior (SIB) and the possibility of treatment-emergent SIB, pharmaceutical companies are now applying more proactive approaches in clinical trials and are considering the value of nonclinical models to predict SIB. The current review summarizes nonclinical approaches to modeling three common risk factors associated with SIB: aggression, impulsivity, and anhedonia. For each risk factor, a general description, advantages and disadvantages, species considerations, nonclinical to clinical translation, and pharmacological validation with respect to treatments associated with SIB are summarized. From this review, several gaps were identified that need to be addressed before use of these nonclinical models can be considered a viable option to predict the relative risk for SIB. Other future directions that may compliment these nonclinical approaches, including the use of selectively-bred or genetically-modified rodent models, transgenic models, gene expression profiling, and biomarker analysis, are discussed. This article was developed with the support of the DruSafe Leadership Group of the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ, www.iqconsortium.org).

A fostering study of the effects of prenatal cocaine exposure: II. Offspring behavioral measures

The impact of rearing condition was assessed in Sprague-Dawley dams given 40 mg/kg cocaine (C40) or saline (LC control) subcutaneously (SC) from gestational days 8-20 and their offspring. Treated pups reared by their biological dams (LC/LC; C40/C40), treated pups reared by surrogate dams (FOS/LC; FOS/C40), and foster pups raised by treated dams (LC/FOS; C40/FOS) were examined. On postnatal day 7 (P7), pups received either 0 (unpaired) 2, 3, or 4 pairings of an odor and footshock and were tested for their aversion to this odor. Foster and LC pups, regardless of rearing condition, exhibited significant odor aversions following either 2, 3, or 4 training trials. In contrast, C40 pups reared by surrogate dams required 4 trials to acquire the aversion, and C40 pups reared by their own dams did not exhibit conditioning even after 4 trials. At P17, no differences were seen among the groups in the aversion formed to an auditory or an olfactory stimulus that was paired with footshock. At P60, shock-elicited aggression among pairs of siblings was examined. Regardless of prenatal exposure condition, offspring reared by dams given cocaine showed a decreased latency to the first aggressive contact, an effect that was evident without any alteration in shock sensitivity. Together these data suggest that being reared by a dam previously exposed to cocaine has an impact on offspring behavioral function apart from the effects of prenatal cocaine exposure per se. The implications of the data regarding the cognitive performance of pups exposed prenatally to cocaine are also discussed.