Modulation of arterial baroreflexes by antisense oligodeoxynucleotides to NMDAR1 receptors in the nucleus tractus solitarius

An antisense oligodeoxynucleotide which specifically blocked the production of the glutamate receptor subtype NMDAR1 was administered to the nucleus t ractus solitarius (NTS) in order to examine the role of this receptor in ba roreflex control of heart rate. Baseline blood pressure and heart rate were unchanged by NTS treatment with the antisense oligodeoxynucleotide to the NMDAR1 receptor subunit. However, the reflex bradycardia evoked in response to the hypertension induced by bolus administration of phenylephrine was s ignificantly attenuated following bilateral NTS antisense oligodeoxynucleot ide treatment. Administration of the corresponding mismatched antisense oli godeoxynucleotide did not significantly alter the reflex bradycardia. These data indicate that NMDAR1 receptors are involved in neurotransmission in t he baroreflex are at the level of the NTS. The specificity of antisense oli godeoxynucleotides may prove to be a useful technique to analyze the role o f receptor subtypes mediating neurotransmission in central pathways. (C) 19 98 Elsevier Science B.V. All rights reserved.