Mammalian reproduction is centrally regulated through the hypothalamic-pituitary-gonadal axis and the primary center of the control is thought to the GnRH neurons. There are two mode of GnRH secretion. Surge mode evokes LH surge and subsequent ovulation in females and pulsatile secretion regulates pulsatile LH secretion that controls follicular maturation. The mechanism for control of GnRH/LH pulse has been called the GnRH pulse generator although neural identity of this mechanism has remained

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... nclear. Recently kisspeptin (kiss) expressing in the medial preoptic area and the arcuate nucleus (ARC) was identified. This neuropeptide has potent function for strong GnRH discharge. Therefore kiss neurons are thought to control the activity of GnRH neurons. ARC kiss neurons are co-expressed Neurokinin B (NKB). NKB also might play important roles in control of pulsatile GnRH/LH secretion although function of NKB has remained unknown. To investigate a mechanism for regulating GnRH/LH pulses and function of NKB in ARC, we study the goat as an animal model. Morphological analysis revealed that ARC kiss neurons formed a cluster and had dense network by their fibers. Next, we established the method to measure neural activity in close proximity to ARC kiss neurons. Using the method, NKB activated the activity in the ARC and pulsatile secretion of LH. These results suggest that cluster of ARC kiss neurons forms a part of the GnRH pulse generator and NKB in ARC kiss neurons play important roles in control of GnRH pulse in goats. S 22 Due to the availability of extensive molecular techniques, and powerful genetics, Drosophila melanogaster has been a successful animal model for the study of development. In the late 1960s, Seymour Benzer started using Drosophila to study how individual genes affect behaviors, and identified the period gene as a regulator of circadian rhythms. More recently, flies have become established as a model for higher order functions, including learning and memory. Besides short-term and long-term memory, which are known in mammals, Drosophila has been used to identify new memory components including middle-term memory and anesthesia-resistant memory. In addition, the pharmacological requirements and genes responsible for each memory component have been identified. I have been using Drosophila to study the physiological role of Mg 2+ block mechanism of the NMDA receptor, and the molecular basis for the spacing effect during long-term memory formation. In this symposium, I will review current advances in Drosophila learning and memory studies and introduce our recent results. Vocal communication is one of the most critical communication ways between individuals in humans. Stuttering is a communication disorder that emerges about 1% of population in any areas and languages in the world. A person who stutters produces speech that is disrupted by involuntary repetitions and prolongations of sounds, words or phrases as well as involuntary silent pauses or blocks. Stuttering also occurs in conjunction with other diseasdes such as Tourette's syndrome. However, the pathogenesis and therapeutic approaches have not been established yet.In this presentation, I introduce the songbird as a potential and unique animal model for studying a communication disorder: stuttering. Songbirds acquire their song patterns by sensorimotor learning, as acquisition of language in humans. We discovered that emergence of context dependent stuttering in songbirds. This stuttering in songbirds fits all criteria for human stuttering in DSM-5. Our accumulating data indicate both environmental/genetic factors and dysfunction of cortical-basal ganglia-thalamic loop are critical for onset of stuttering.