Two independent forms of activity-dependent potentiation regulate electrical transmission at mixed synapses on the Mauthner cell

• Published in: Brain research Vol. 1487; pp. 173 - 182
• Main Authors: Cachope, Roger, Pereda, Alberto E.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 03.12.2012; Elsevier
• Subjects: Animals; Auditory; Biological and medical sciences; brain; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Calcium-Calmodulin-Dependent Protein Kinase Type 2 - metabolism; CaMKII; Cell physiology; Connexin 36; Cyclic AMP-Dependent Protein Kinases; Cyclic AMP-Dependent Protein Kinases - metabolism; Dopamine; Dopamine - physiology; Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation; Electrical Synapses; Electrical Synapses - physiology; Endocannabinoid; Endocannabinoids; Endocannabinoids - physiology; Fundamental and applied biological sciences. Psychology; Gap junction; gap junctions; Humans; kinases; Long-Term Potentiation; Long-Term Potentiation - physiology; metabolism; Miscellaneous; Molecular and cellular biology; Nerve Endings; Nerve Endings - physiology; Neurology; NMDA; phosphotransferases (kinases); physiology; PKA; receptors; Receptors, N-Methyl-D-Aspartate; Receptors, N-Methyl-D-Aspartate - physiology; Synaptic Transmission; Synaptic Transmission - physiology; vertebrates; Vertebrates: nervous system and sense organs; Dopamine; CaMKII; Auditory; Endocannabinoid; Long-term potentiation; PKA; NMDA; Gap junction; Connexin 36; Potentiation; calmodulin-dependent protein kinase; Enzyme; Transferases; Transmission; Cell junction; Review; Catecholamine; Cannabinoid; Connexin; Hearing; Synapse; Synaptic plasticity; Neurotransmitter; Ca
• ISSN: 0006-8993; 1872-6240; 1872-6240
• DOI: 10.1016/j.brainres.2012.05.059

Mixed (electrical and chemical) synaptic contacts on the Mauthner cells, known as Club endings, constitute a valuable model for the study of vertebrate electrical transmission. While electrical synapses are still perceived by many as passive intercellular channels that lack modifiability, a wealth of experimental evidence shows that gap junctions at Club endings are subject to dynamic regulatory control by two independent activity-dependent mechanisms that lead to potentiation of electrical transmission. One of those mechanisms relies on activation of NMDA receptors and postsynaptic CaMKII. A second mechanism relies on mGluR activation and endocannabinoid production and is indirectly mediated via the release of dopamine from nearby varicosities, which in turn leads to potentiation of the synaptic response via a PKA-mediated postsynaptic mechanism. We review here these two forms of potentiation and their signaling mechanisms, which include the activation of two kinases with well-established roles as regulators of synaptic strength, as well as the functional implications of these two forms of potentiation. Special Issue entitled Electrical Synapses.