CHRNA7, coding the neuronal nicotinic acetylcholine receptor alpha7 subunit. alpha7-containing receptors are known to improve prepulse inhibition, pre-attentive and attentive states. For bipolar disorder In bipolar disorder, one commonly identified endophenotype is a deficit in face emotion labeling, which is found in both individuals with bipolar disorder and in individuals who are "at risk" (i.e., have a first degree relative with bipolar disorder). Using fMRI, this endophenotype has been linked to dysfunction in the dorsolateral and ventrolateral prefrontal cortex, anterior cingulate cortex, striatum, and amygdala. A polymorphism in the CACNA1C gene coding for the voltage-dependent calcium channel Cav1.2 has been found to be associated with deficits in facial emotion recognition. For suicide The endophenotype concept has also been used in suicide studies. Personality characteristics can be viewed as endophenotypes that may exert a diathesis effect on an individual's susceptibility to suicidal behavior. Although the exact identification of these endophenotypes is controversial, certain traits such as impulsivity and aggression are commonly cited risk factors. One such genetic basis for one of these at-risk endophenotypes has been suggested in 2007 to be the gene coding for the serotonin receptor 5-HT1B, known to be relevant in aggressive behaviors. See also Biomarker References Biological psychiatry Bioindicators Behavioural genetics