In conclusion, the rat primary motor cortex appears to be organized into irregularly shaped patches of cortex devoted to particular movements. The location of major subdivisions such as the forelimb or hindlimb areas is somatotopic and is consistent from animal to animal, but the internal organization of the pattern of movements represented within major subdivisions varies significantly between animals. The motor cortex includes both agranular primary motor cortex (AgL) and, in addition, a significant amount of the bordering granular somatic sensory cortex (Gr(SI)), as well as the rostral portion of the taste sensory insular or claustrocortex (Cl). The rat frontal cortex also contains a second, rostral motor representation of the forelimb, trunk and hindlimb, which is somatotopically organized and may be the rat's supplementary motor area. Both of these motor representations give rise to direct corticospinal projections, some of which may make monosynaptic connections with cervical enlargement motoneurons. Medial to the primary motor cortex, in cytoarchitectonic field AgM, is what appears to be part of the rat's frontal eye fields, a region which also includes the vibrissae motor representation. The somatic motor cortical output organization pattern in the rat is remarkably similar to that seen in the primate, whose primary, supplementary and frontal eye field cortical motor regions have been extensively studied.

Abuse in childhood may constitute an environmental risk factor for the development of trait impulsivity and aggression as well as suicide attempts in depressed adults. Alternatively, impulsivity and aggression may be inherited traits underlying both childhood abuse and suicidal behavior in adulthood disorders. Additional research is needed to estimate the relative contributions of heredity and environmental experience to the development of impulsivity, aggression, and suicidal behavior.

Individuals with bipolar disorder possess a substantial burden of general medical comorbidity, and are occurring at an earlier age than in the general VA patient population, suggesting the need for earlier detection and treatment for patients with bipolar disorder.

During a depressive episode, the subjective perception of stressful life events may be more germane to suicidal expression than the objective quantity of such events. A more optimistic perceptual set, despite equivalent objective severity of depression, may modify hopelessness and may protect against suicidal behavior during periods of risk, such as major depression. Assessment of reasons for living should be included in the evaluation of suicidal patients.