While
Htt null KO mice do not survive to birth (Duyao et al., 1995; Nasir et al., 1995; Zeitlin et al., 1995), mice expressing a 50 % reduction of endogenous htt levels reveal cognitive and motor deficits (Nasir et al., 1995) and significant decreases in the number of neurons in globus pallidus and subthalamic nucleus (O'Kusky et al., 199
Htt null KO mice do not survive to birth (Duyao et al., 1995; Nasir et al., 1995; Zeitlin et al., 1995), mice expressing a 50 % reduction of endogenous
htt levels reveal cognitive and motor deficits (Nasir et al., 1995) and significant decreases in the number of neurons in globus pallidus and subthalamic nucleus (O'Kusky et al., 199
htt levels reveal cognitive and motor deficits (Nasir et al., 1995) and significant
decreases in the number of neurons in globus pallidus and subthalamic nucleus (O'Kusky et al., 1999).
Knocking down the endogenous
htt protein resulted in significant
decrease in body weight and hyperactive behavior in the open field.
Consistent with preclinical studies, adults with depression have been reported to have multiple alterations of the hypothalamic pituitary adrenal axis (9), increased cerebrospinal fluid corticotropin - releasing hormone (10), elevated cerebrospinal fluid norepinephrine concentration (11),
decreased cortical γ - aminobutyric acid measured in vivo using proton magnetic resonance spectroscopy (12), and multiple indicators of altered serotonin (5 - HT) functioning (13), including reduced serotonin transporter (5 -
HTT) availability as evidenced by reduced [123I] β - CIT spect binding (14).