Figure 1. Schematic drawing of a mid-sagittal section through the rat brain summarizing the organization of the luteinizing hormone-releasing hormone (LHRH) neuronal system. Note that the medial preoptic area (POA) contains the highest density in LHRH cell bodies in the rat, whereas another group of neuroendocrine LHRH neurons can be found in the arcuate nucleus of the hypothalamus of the human brain. Abbreviations: Amyg, amygdala; AON, anterior olfactory nucleus; AP, anterior pituitary; BST, bed nuclei stria terminalis; CG, central gray; CP, caudoputamen; CTX, cerebral cortex; Hab, habenula; HF, hippocampal fissure; IC, inferior colliculus; IP, interposed nucleus; LDT, lateral dorsal tegmental nucleus; Mam, mammillary body; ME, median eminence; MidThal, midthalamus; NTS, nucleus of the solitary tract; OB, olfactory bulb; OT, olfactory tubercle; PB, parabrachial nucleus; PreCBL, precerebellum; POA, preoptic area; PPN, peduncolopontine nucleus; SC, superior colliculus; SEP, septal region; SI, substantia innominata; SN, substantia nigra; Sp.V, spinal nucleus of the trigeminal nerve; Sp.Cd., spinal cord; SubThal, subthalamus; Vest, vestibular area; VTA, ventral tegmental area.