Role of glutamate and NMDA receptors in the descending limb of the spinobulbospinal micturition reflex pathway of the rat

• Published in: Neuroscience letters Vol. 183; no. 1; pp. 58 - 61
• Main Authors: Matsumoto, G., Hisamitsu, T., de Groat, W.C.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 02-01-1995; Elsevier
• Subjects: Animals; Biological and medical sciences; Dizocilpine Maleate - pharmacology; Dose-Response Relationship, Drug; Electric Stimulation; Female; Fundamental and applied biological sciences. Psychology; Glutamate; Glutamic Acid - metabolism; Micturition; MK-801; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Muscle Contraction; Neural Pathways; NMDA receptor; Pontine micturition center; Rats; Rats, Wistar; Receptors, N-Methyl-D-Aspartate - metabolism; Reflex - physiology; Urinary Bladder - physiology; Vertebrates: nervous system and sense organs; MK-801; Micturition; NMDA receptor; Glutamate; Pontine micturition center; Spinal cord; Rat; Motor pathway; Rodentia; Central nervous system; Glutamate receptor; Muscle contraction; Pressure; Spinobulbospinal reflex; Vertebrata; Mammalia; Urinary bladder; Excitatory aminoacid; Neurotransmitter; Antagonist
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/0304-3940(94)11114-X

MK-801, an NMDA receptor antagonist administered intravenously or intrathecally to the L6-S1 spinal cord inhibited in a dose dependent manner the amplitude of isovolumetric bladder contractions evoked by electrical stimulation in the pontine micturition center (PMC) in urethane anesthetized rats. The mean threshold dose of MK-801 was 10 ± 6 μg/kg i.v. and 10 ± 1 μg i.t. Bladder contractions were completely inhibited at doses ranging from 300 to 3000 μg/kg i.v. and from 18 to 48μg i.t. These data indicate that NMDA glutamatergic receptors play an important role in excitatory transmission in the descending pathway from the PMC to the spinal segmental circuitry involved in the control of the urinary bladder.