{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,17]],"date-time":"2026-10-17T13:03:45Z","timestamp":1792242225669,"version":"4.4.0"},"reference-count":23,"publisher":"The Company of Biologists","issue":"1","license":[{"start":{"date-parts":[[1994,1,1]],"date-time":"1994-01-01T00:00:00Z","timestamp":757382400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/www.biologists.com\/user-licence-1-1\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[1994,1,1]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n               <jats:p>The rhythmically active heart interneuron HN(5) in the medicinal leech exhibits two distinct activity states, which have been associated with different coordination states of the two hearts. During the active state, it discharges high-frequency bursts of action potentials interrupted by rhythmic inhibitory input from other interneurons. In the inactive state, the same cell receives rhythmic inhibition but the membrane potential remains subthreshold between these volleys, producing few or no action potentials. We investigated differences in the membrane properties of the cell during the active and inactive states. The membrane potential in the active state oscillates on average between about -56\u00b16 mV (S.D.) and -45\u00b17 mV; the mean oscillation amplitude is 11\u00b14 mV. In the inactive state, the membrane potential oscillates on average between -58\u00b16 mV and -55\u00b16 mV with a mean amplitude of 3\u00b11 mV. The overall conductance of an HN(5) interneuron during the active state is approximately 10 nS lower than that during the inactive state, indicating that an outward current is turned off during the active state or turned on during the inactive state. This outward current is not voltage-dependent in the range -80 mV to -10 mV, as shown in voltage-clamp experiments by a linear current\u2013voltage relationship. The reversal potential of this current is approximately -60 mV, indicating that chloride or potassium ions underlie the current. Using dynamic-clamp, we show that by adding an artificial current with a linear voltage-dependence (leak conductance) to an HN(5) interneuron (conductance 15 nS, reversal potential -60 mV), the cell can be transferred from its active to its inactive state.<\/jats:p>","DOI":"10.1242\/jeb.186.1.157","type":"journal-article","created":{"date-parts":[[2021,4,25]],"date-time":"2021-04-25T03:38:12Z","timestamp":1619321892000},"page":"157-171","source":"Crossref","is-referenced-by-count":33,"title":["Switching in the activity state of an interneuron that controls coordination of the hearts in the medicinal leech (<i>Hirudo medicinalis<\/i>)"],"prefix":"10.1242","volume":"186","author":[{"given":"S.","family":"Gramoll","sequence":"first","affiliation":[{"name":"Emory University Department of Biology , , 1510 Clifton Road, Atlanta, GA 30322, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"Schmidt","sequence":"additional","affiliation":[{"name":"Emory University Department of Biology , , 1510 Clifton Road, Atlanta, GA 30322, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R. L.","family":"Calabrese","sequence":"additional","affiliation":[{"name":"Emory University Department of Biology , , 1510 Clifton Road, Atlanta, GA 30322, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"237","published-online":{"date-parts":[[1994,1,1]]},"reference":[{"key":"2023051507452897500_JEXBIO_186_1_157C1","doi-asserted-by":"publisher","first-page":"746","DOI":"10.1523\/JNEUROSCI.11-03-00746.1991","article-title":"Calcium currents and graded synaptic transmission between heart interneurons of the leech","volume":"11","author":"Angstadt","year":"1991","journal-title":"J. Neurosci"},{"key":"2023051507452897500_JEXBIO_186_1_157C2","doi-asserted-by":"publisher","first-page":"111","DOI":"10.1007\/BF00611251","article-title":"The neural control of alternate heartbeat coordination states in the leech, Hirudo medicinalis","volume":"122","author":"Calabrese","year":"1977","journal-title":"J. comp. 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