Representative recording site. A, Schematic diagram of a coronal section at the level of the LMN at −4.52 mm from bregma, modified from the atlas of Paxinos and Watson (1998). The dashed box depicts the outline of the region from which the photomicrograph (B) was taken.B, Photomicrograph of a coronal section stained for cresyl violet illustrating the electrode track passing through the LMN.Arrow indicates the ventral tip of the electrode track.3V, Third ventricle; CA2–3, CA2, CA3 of hippocampus; cp, cerebral peduncle; DG, dentate gyrus; F, nucleus of fields of Forel;f, fornix; ic, internal capsule;LH, lateral hypothalamus; LM, lateral mammillary nuclei; LV, lateral ventricle;MM, medial mammillary nuclei; ML, lateral aspect of medial mammillary nuclei; ml, medial lemniscus; pm, premammillary tract; PH, posterior hypothalamus; PR, prerubral field;SNR, substantia nigra pars reticulata;SuM, supramammillary nuclei; VTM, ventral tuberomammillary nuclei; ZI, zona incerta. Scale bar, 0.5 mm.