Ischemic-LTP in striatal spiny neurons of both direct and indirect pathway requires the activation of D1-like receptors and NO/soluble guanylate cyclase/cGMP transmission

J Cereb Blood Flow Metab. 2013 Feb;33(2):278-86. doi: 10.1038/jcbfm.2012.167. Epub 2012 Nov 14.

Abstract

Striatal medium-sized spiny neurons (MSNs) are highly vulnerable to ischemia. A brief ischemic insult, produced by oxygen and glucose deprivation (OGD), can induce ischemic long-term potentiation (i-LTP) of corticostriatal excitatory postsynaptic response. Since nitric oxide (NO) is involved in the pathophysiology of brain ischemia and the dopamine D1/D5-receptors (D1-like-R) are expressed in striatal NOS-positive interneurons, we hypothesized a relation between NOS-positive interneurons and striatal i-LTP, involving D1R activation and NO production. We investigated the mechanisms involved in i-LTP induced by OGD in corticostriatal slices and found that the D1-like-R antagonist SCH-23390 prevented i-LTP in all recorded MSNs. Immunofluorescence analysis confirmed the induction of i-LTP in both substance P-positive, (putative D1R-expressing) and adenosine A2A-receptor-positive (putative D2R-expressing) MSNs. Furthermore, i-LTP was dependent on a NOS/cGMP pathway since pharmacological blockade of NOS, guanylate-cyclase, or PKG prevented i-LTP. However, these compounds failed to prevent i-LTP in the presence of a NO donor or cGMP analog, respectively. Interestingly, the D1-like-R antagonism failed to prevent i-LTP when intracellular cGMP was pharmacologically increased. We propose that NO, produced by striatal NOS-positive interneurons via the stimulation of D1-like-R located on these cells, is critical for i-LTP induction in the entire population of MSNs involving a cGMP-dependent pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzazepines / pharmacology
  • Brain Ischemia / metabolism*
  • Brain Ischemia / pathology
  • Brain Ischemia / physiopathology
  • Corpus Striatum / metabolism*
  • Corpus Striatum / physiopathology
  • Cyclic GMP / metabolism*
  • Glucose / metabolism
  • Guanylate Cyclase / metabolism*
  • Interneurons / metabolism*
  • Interneurons / pathology
  • Long-Term Potentiation / drug effects
  • Male
  • Nerve Tissue Proteins / metabolism*
  • Nitric Oxide / metabolism*
  • Nitric Oxide Donors / pharmacology
  • Oxygen / metabolism
  • Rats
  • Rats, Wistar
  • Receptor, Adenosine A2A / metabolism
  • Receptors, Dopamine D1 / antagonists & inhibitors
  • Receptors, Dopamine D1 / metabolism*
  • Receptors, Dopamine D5 / antagonists & inhibitors
  • Receptors, Dopamine D5 / metabolism
  • Synaptic Transmission*

Substances

  • Benzazepines
  • Nerve Tissue Proteins
  • Nitric Oxide Donors
  • Receptor, Adenosine A2A
  • Receptors, Dopamine D1
  • SCH 23390
  • Receptors, Dopamine D5
  • Nitric Oxide
  • Guanylate Cyclase
  • Cyclic GMP
  • Glucose
  • Oxygen