BRS

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BRS Neuroanatomy

Paraventricular and supraoptic nuclei • regulate water balance • produce ADH and oxytocin • destruction causes diabetes insipidus • paraventricular nucleus projects to autonomic nuclei of brainstem and spinal cord Anterior nucleus • thermal regulation (dissipation of heat) • stimulates parasympathetic NS • destruction results in hyperthermia Preoptic area • contains sexually dimorphic nucleus • regulates release of gonadotropic hormones

Dorsomedial nucleus • stimulation results in obesity and savage behavior Posterior nucleus • thermal regulation (conservation of heat) • destruction results in inability to thermoregulate • stimulates the sympathetic NS

Lateral nucleus • stimulation induces eating • destruction results in starvation Mammillary body • receives input from hippocampal formation via fornix • projects to anterior nucleus of thalamus

Midbrain

• contains hemorrhagic lesions in Wernicke encephalopathy Ventromedial nucleus • satiety center • destruction results in obesity and savage behavior

Suprachiasmatic nucleus • receives input from retina • controls circadian rhythms

CN III

Pons

Arcuate nucleus • produces hypothalamic-releasing factors • contains DOPA-ergic neurons that inhibit prolactin release

FIGURE 13.5. Major hypothalamic nuclei and their functions. ADH, antidiuretic hormone; DOPA, dihydroxyphenylalanine; NS, nervous system. (Modified with permission from Fix JD. High-Yield Neuroanatomy . 3rd ed. Lippincott Williams & Wilkins; 2005:132.)

■ contains the medial preoptic nucleus , which regulates the release of gonadotropic hor mones from the adenohypophysis. The medial preoptic nucleus contains the sexually dimorphic nucleus, whose development is dependent on testosterone levels. 2. Supraoptic region ■ lies superior to the optic chiasm. a. Suprachiasmatic nucleus ■ receives direct input from the retina. ■ plays a role in the control of circadian rhythms . b. Anterior nucleus ■ plays a role in temperature regulation. ■ stimulates the parasympathetic nervous system. ■ destruction results in hyperthermia. c. Paraventricular nucleus ■ neurosecretory cells synthesize and release antidiuretic hormone ( ADH ), oxyto cin , and corticotropin-releasing hormone ( CRH ). ■ regulates water balance (conservation of water). ■ gives rise to the supraopticohypophyseal tract, which projects to the neurohypophysis. ■ destruction results in diabetes insipidus . d. Supraoptic nucleus ■ synthesizes ADH and oxytocin . ■ projects to the neurohypophysis via the supraopticohypophyseal tract. 3. Tuberal region ■ lies superior to the tuber cinereum. a. Dorsomedial nucleus (see Figure 13.4) ■ results in rage when stimulated. b. Ventromedial nucleus (see Figure 13.4) ■ satiety center . ■ when stimulated, inhibits the urge to eat. ■ bilateral destruction involved with hyperphagia, obesity, and savage behavior. c. Arcuate (infundibular) nucleus ■ located in the tuber cinereum.

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