PMC

TPH mRNA and c-fos mRNA expression in CNS. (a-d) Photomicrographs of photo emulsion-dipped sections obtained from Y1^-/- (a and c) and control (b and d) mice after in situ hybridization for TPH mRNA. The dorsal raphe nucleus is depicted in a and b, and the pontine nucleus is shown in c and d. Aq, aqueduct. (e and f) c-fos mRNA expression in the central nucleus of the amygdala of Y1^-/- and control mice, respectively, after exposure to the RI test. (Scale bar = 40 μm.)

Neuropeptide mRNA expression in the CNS. Altered neuropeptide mRNA levels in areas involved in aggression and feeding in Y1-deficient mice. High-power photomicrographs of photo emulsion-dipped sections obtained from control (a, c, e, g, i, and k) and Y1^-/- (b, d, f, h, j, and l) mice after in situ hybridization for neuropeptide mRNAs. NPY in the accessory olfactory bulb (a and b), GnRH in scattered neurons of the medial septal nucleus (c and d), CART in the medial (e and f) and central (g and h) amygdaloid nucleus and the arcuate nucleus (i and j), and POMC in the arcuate nucleus (k and l) are depicted. (Scale bar = 100 μm.)

Territorial aggression and its reduction after 5-HT1A agonist treatment. (a and b) Territorial aggression in group-housed (a) and individually housed (b) mice after being tested in the RI paradigm. Frequencies [n] of aggressive behaviors such as tail rattling, aggressive grooming, and biting in control and Y1^-/- mice are shown. Data represent means ± SEM (n = 9-12 mice). Significant post hoc effects vs. control animals are indicated by asterisks (^*, P < 0.05; ^**, P < 0.01; ^***, P < 0.001). (c) Territorial aggression in individually housed mice after being tested in the RI paradigm. Latencies [s] of aggressive behaviors such as tail rattling, aggressive grooming, and biting in control and Y1^-/- mice are shown. Data represent means ± SEM (n = 10-12 mice). Significant post hoc effects vs. control animals are indicated by asterisks (^*, P < 0.05; ^***, P < 0.001). (d) Reduction in territorial aggressive behavior in the RI paradigm 25 min after s.c. treatment with different doses (saline, 0.1 or 1.0 mg/kg) of a 5HT-1A agonist (8-OH-DPAT). Latencies [s] of aggressive behaviors such as tail rattling, aggressive grooming, and biting in control and Y1^-/- mice are shown, dependent on different drug doses (mg/kg of body weight). Data represent means ± SEM (n = 9-10 mice). Significant post hoc effects vs. control animals are indicated by asterisks (^*, P < 0.05; ^**, P < 0.01).