Tags

Type your tag names separated by a space and hit enter

Mu opioid receptor activation inhibits GABAergic inputs to basolateral amygdala neurons through Kv1.1/1.2 channels.
J Neurophysiol. 2006 Apr; 95(4):2032-41.JN

Abstract

The basolateral amygdala (BLA) is the major amygdaloid nucleus distributed with mu opioid receptors. The afferent input from the BLA to the central nucleus of the amygdala (CeA) is considered important for opioid analgesia. However, little is known about the effect of mu opioids on synaptic transmission in the BLA. In this study, we examined the effect of mu opioid receptor stimulation on the inhibitory and excitatory synaptic inputs to CeA-projecting BLA neurons. BLA neurons were retrogradely labeled with a fluorescent tracer injected into the CeA of rats. Whole cell voltage-clamp recordings were performed on labeled BLA neurons in brain slices. The specific mu opioid receptor agonist, (D-Ala2,N-Me-Phe4,Gly5-ol)-enkephalin (DAMGO, 1 microM), significantly reduced the frequency of miniature inhibitory postsynaptic currents (mIPSCs) in 77% of cells tested. DAMGO also significantly decreased the peak amplitude of evoked IPSCs in 75% of cells examined. However, DAMGO did not significantly alter the frequency of mEPSCs or the peak amplitude of evoked EPSCs in 90% and 75% of labeled cells, respectively. Bath application of the Kv channel blockers, 4-AP (Kv1.1, 1.2, 1.3, 1.5, 1.6, 3.1, 3.2), alpha-dendrotoxin (Kv1.1, 1.2, 1.6), dendrotoxin-K (Kv1.1), or tityustoxin-Kalpha (Kv1.2) each blocked the inhibitory effect of DAMGO on mIPSCs. Double immunofluorescence labeling showed that some of the immunoreactivities of Kv1.1 and Kv1.2 were colocalized with synaptophysin in the BLA. This study provides new information that activation of presynaptic mu opioid receptors primarily attenuates GABAergic synaptic inputs to CeA-projecting neurons in the BLA through a signaling mechanism involving Kv1.1 and Kv1.2 channels.

Authors+Show Affiliations

Department of Anesthesiology , Pennsylvania State University College of Medicine, The Milton S. Hershey Medical Center, Hershey Pennsylvania, USA.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural

Language

eng

PubMed ID

16306173

Citation

Finnegan, Thomas F., et al. "Mu Opioid Receptor Activation Inhibits GABAergic Inputs to Basolateral Amygdala Neurons Through Kv1.1/1.2 Channels." Journal of Neurophysiology, vol. 95, no. 4, 2006, pp. 2032-41.
Finnegan TF, Chen SR, Pan HL. Mu opioid receptor activation inhibits GABAergic inputs to basolateral amygdala neurons through Kv1.1/1.2 channels. J Neurophysiol. 2006;95(4):2032-41.
Finnegan, T. F., Chen, S. R., & Pan, H. L. (2006). Mu opioid receptor activation inhibits GABAergic inputs to basolateral amygdala neurons through Kv1.1/1.2 channels. Journal of Neurophysiology, 95(4), 2032-41.
Finnegan TF, Chen SR, Pan HL. Mu Opioid Receptor Activation Inhibits GABAergic Inputs to Basolateral Amygdala Neurons Through Kv1.1/1.2 Channels. J Neurophysiol. 2006;95(4):2032-41. PubMed PMID: 16306173.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Mu opioid receptor activation inhibits GABAergic inputs to basolateral amygdala neurons through Kv1.1/1.2 channels. AU - Finnegan,Thomas F, AU - Chen,Shao-Rui, AU - Pan,Hui-Lin, Y1 - 2005/11/23/ PY - 2005/11/25/pubmed PY - 2006/9/26/medline PY - 2005/11/25/entrez SP - 2032 EP - 41 JF - Journal of neurophysiology JO - J. Neurophysiol. VL - 95 IS - 4 N2 - The basolateral amygdala (BLA) is the major amygdaloid nucleus distributed with mu opioid receptors. The afferent input from the BLA to the central nucleus of the amygdala (CeA) is considered important for opioid analgesia. However, little is known about the effect of mu opioids on synaptic transmission in the BLA. In this study, we examined the effect of mu opioid receptor stimulation on the inhibitory and excitatory synaptic inputs to CeA-projecting BLA neurons. BLA neurons were retrogradely labeled with a fluorescent tracer injected into the CeA of rats. Whole cell voltage-clamp recordings were performed on labeled BLA neurons in brain slices. The specific mu opioid receptor agonist, (D-Ala2,N-Me-Phe4,Gly5-ol)-enkephalin (DAMGO, 1 microM), significantly reduced the frequency of miniature inhibitory postsynaptic currents (mIPSCs) in 77% of cells tested. DAMGO also significantly decreased the peak amplitude of evoked IPSCs in 75% of cells examined. However, DAMGO did not significantly alter the frequency of mEPSCs or the peak amplitude of evoked EPSCs in 90% and 75% of labeled cells, respectively. Bath application of the Kv channel blockers, 4-AP (Kv1.1, 1.2, 1.3, 1.5, 1.6, 3.1, 3.2), alpha-dendrotoxin (Kv1.1, 1.2, 1.6), dendrotoxin-K (Kv1.1), or tityustoxin-Kalpha (Kv1.2) each blocked the inhibitory effect of DAMGO on mIPSCs. Double immunofluorescence labeling showed that some of the immunoreactivities of Kv1.1 and Kv1.2 were colocalized with synaptophysin in the BLA. This study provides new information that activation of presynaptic mu opioid receptors primarily attenuates GABAergic synaptic inputs to CeA-projecting neurons in the BLA through a signaling mechanism involving Kv1.1 and Kv1.2 channels. SN - 0022-3077 UR - https://www.unboundmedicine.com/medline/citation/16306173/Mu_opioid_receptor_activation_inhibits_GABAergic_inputs_to_basolateral_amygdala_neurons_through_Kv1_1/1_2_channels_ L2 - http://www.physiology.org/doi/full/10.1152/jn.01004.2005?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -