How is the hypothalamus involved in sleep? . a)cell clusters in the hypothalamus stimulate the production of relatively slow alpha waves, signaling the transition from deep relaxation to sleep.. b)the hypothalamus triggers the pituitary gland in the endocrine system to produce the hormone thyroxin, which leads you to sleep.. c)during sleep the hypothalamus stimulates the production of free radicals, molecules that are toxic to neurons, which weakens unused connections.. d)in response to decreasing light the hypothalamus' suprachiastmatic nucleus causes the pineal gland to increase production