@ARTICLE{Shen1986-fm,
  title    = "Turtle hippocampal cortex contains distinct cell types,
              burst-firing neurons, and an epileptogenic subfield",
  author   = "Shen, J M and Kriegstein, A R",
  abstract = "The dorsal and medial telencephalon of reptiles consists of a
              simple trilaminar cortex. The turtle dorsal cortex has been
              identified as a favorable physiological preparation that may bear
              a phylogenetic relationship to mammalian neocortex. While
              anatomical studies have likened the reptilian medial cortical
              region to mammalian hippocampus, its physiological properties
              have not been explored. We therefore used intracellular and
              extracellular recording techniques to examine the cellular and
              synaptic physiology of turtle ``hippocampal'' or medial cortex.
              Turtle medial cortex contains two principal classes of neurons,
              pyramidal cells and stellate neurons. Recordings with Lucifer
              yellow CH (LY)-filled microelectrodes allowed us to correlate the
              physiological properties of medial cortical neurons with their
              cellular morphology. Pyramidal neurons were situated in a single
              cellular layer and had spiny apical dendrites extending into the
              molecular layer. These cells fired relatively long-duration
              action potentials (APs) and showed frequency adaptation to
              suprathreshold current pulse injections. Stellate cells were
              usually found in the subcellular and molecular layers and had
              aspiny dendrites. In contrast to pyramidal cells, they fired
              brief APs and displayed no frequency adaptation. A discrete
              population of cells in the dorsal portion of medial cortex (DMC)
              was capable of bursting endogenously or in response to synaptic
              activation. Bursts usually contained an underlying slow
              depolarization and often occurred at regular intervals.
              Intracellular LY injections confirmed that these cells were
              pyramidal in morphology. Electrical stimulation of afferent
              fibers revealed that pyramidal cells and stellate neurons
              differed in their synaptic responses. In ventral medial cortex
              (VMC), afferent stimulation evoked a multiphasic response in most
              pyramidal cells, whereas stellate cells were synaptically
              excited. Orthodromic activation of DMC bursting cells resulted in
              a powerful excitation--often a short burst--and subsequent
              inhibition. Stellate neurons in DMC also had a biphasic synaptic
              response consisting of both an early excitation and a late
              inhibition. Experiments using intracellular chloride (Cl-)
              injection or focal bicuculline application suggested that part of
              the inhibitory component of the pyramidal cell synaptic response
              was dependent on a gamma-aminobutyric acid (GABA)-mediated
              increase in Cl- conductance. These results correlated with our
              immunohistochemical studies that revealed the presence of
              GABAergic neurons in medial cortex.(ABSTRACT TRUNCATED AT 400
              WORDS)",
  journal  = "J Neurophysiol",
  volume   =  56,
  number   =  6,
  pages    = "1626--1649",
  month    =  dec,
  year     =  1986,
  address  = "United States",
  language = "en"
}

{"_id":"d3cTJb6oG8iYsTXD8","bibbaseid":"shen-kriegstein-turtlehippocampalcortexcontainsdistinctcelltypesburstfiringneuronsandanepileptogenicsubfield-1986","author_short":["Shen, J M","Kriegstein, A R"],"bibdata":{"bibtype":"article","type":"article","title":"Turtle hippocampal cortex contains distinct cell types, burst-firing neurons, and an epileptogenic subfield","author":[{"propositions":[],"lastnames":["Shen"],"firstnames":["J","M"],"suffixes":[]},{"propositions":[],"lastnames":["Kriegstein"],"firstnames":["A","R"],"suffixes":[]}],"abstract":"The dorsal and medial telencephalon of reptiles consists of a simple trilaminar cortex. The turtle dorsal cortex has been identified as a favorable physiological preparation that may bear a phylogenetic relationship to mammalian neocortex. While anatomical studies have likened the reptilian medial cortical region to mammalian hippocampus, its physiological properties have not been explored. We therefore used intracellular and extracellular recording techniques to examine the cellular and synaptic physiology of turtle ``hippocampal'' or medial cortex. Turtle medial cortex contains two principal classes of neurons, pyramidal cells and stellate neurons. Recordings with Lucifer yellow CH (LY)-filled microelectrodes allowed us to correlate the physiological properties of medial cortical neurons with their cellular morphology. Pyramidal neurons were situated in a single cellular layer and had spiny apical dendrites extending into the molecular layer. These cells fired relatively long-duration action potentials (APs) and showed frequency adaptation to suprathreshold current pulse injections. Stellate cells were usually found in the subcellular and molecular layers and had aspiny dendrites. In contrast to pyramidal cells, they fired brief APs and displayed no frequency adaptation. A discrete population of cells in the dorsal portion of medial cortex (DMC) was capable of bursting endogenously or in response to synaptic activation. Bursts usually contained an underlying slow depolarization and often occurred at regular intervals. Intracellular LY injections confirmed that these cells were pyramidal in morphology. Electrical stimulation of afferent fibers revealed that pyramidal cells and stellate neurons differed in their synaptic responses. In ventral medial cortex (VMC), afferent stimulation evoked a multiphasic response in most pyramidal cells, whereas stellate cells were synaptically excited. Orthodromic activation of DMC bursting cells resulted in a powerful excitation–often a short burst–and subsequent inhibition. Stellate neurons in DMC also had a biphasic synaptic response consisting of both an early excitation and a late inhibition. Experiments using intracellular chloride (Cl-) injection or focal bicuculline application suggested that part of the inhibitory component of the pyramidal cell synaptic response was dependent on a gamma-aminobutyric acid (GABA)-mediated increase in Cl- conductance. These results correlated with our immunohistochemical studies that revealed the presence of GABAergic neurons in medial cortex.(ABSTRACT TRUNCATED AT 400 WORDS)","journal":"J Neurophysiol","volume":"56","number":"6","pages":"1626–1649","month":"December","year":"1986","address":"United States","language":"en","bibtex":"@ARTICLE{Shen1986-fm,\n title = \"Turtle hippocampal cortex contains distinct cell types,\n burst-firing neurons, and an epileptogenic subfield\",\n author = \"Shen, J M and Kriegstein, A R\",\n abstract = \"The dorsal and medial telencephalon of reptiles consists of a\n simple trilaminar cortex. The turtle dorsal cortex has been\n identified as a favorable physiological preparation that may bear\n a phylogenetic relationship to mammalian neocortex. While\n anatomical studies have likened the reptilian medial cortical\n region to mammalian hippocampus, its physiological properties\n have not been explored. We therefore used intracellular and\n extracellular recording techniques to examine the cellular and\n synaptic physiology of turtle ``hippocampal'' or medial cortex.\n Turtle medial cortex contains two principal classes of neurons,\n pyramidal cells and stellate neurons. Recordings with Lucifer\n yellow CH (LY)-filled microelectrodes allowed us to correlate the\n physiological properties of medial cortical neurons with their\n cellular morphology. Pyramidal neurons were situated in a single\n cellular layer and had spiny apical dendrites extending into the\n molecular layer. These cells fired relatively long-duration\n action potentials (APs) and showed frequency adaptation to\n suprathreshold current pulse injections. Stellate cells were\n usually found in the subcellular and molecular layers and had\n aspiny dendrites. In contrast to pyramidal cells, they fired\n brief APs and displayed no frequency adaptation. A discrete\n population of cells in the dorsal portion of medial cortex (DMC)\n was capable of bursting endogenously or in response to synaptic\n activation. Bursts usually contained an underlying slow\n depolarization and often occurred at regular intervals.\n Intracellular LY injections confirmed that these cells were\n pyramidal in morphology. Electrical stimulation of afferent\n fibers revealed that pyramidal cells and stellate neurons\n differed in their synaptic responses. In ventral medial cortex\n (VMC), afferent stimulation evoked a multiphasic response in most\n pyramidal cells, whereas stellate cells were synaptically\n excited. Orthodromic activation of DMC bursting cells resulted in\n a powerful excitation--often a short burst--and subsequent\n inhibition. Stellate neurons in DMC also had a biphasic synaptic\n response consisting of both an early excitation and a late\n inhibition. Experiments using intracellular chloride (Cl-)\n injection or focal bicuculline application suggested that part of\n the inhibitory component of the pyramidal cell synaptic response\n was dependent on a gamma-aminobutyric acid (GABA)-mediated\n increase in Cl- conductance. These results correlated with our\n immunohistochemical studies that revealed the presence of\n GABAergic neurons in medial cortex.(ABSTRACT TRUNCATED AT 400\n WORDS)\",\n journal = \"J Neurophysiol\",\n volume = 56,\n number = 6,\n pages = \"1626--1649\",\n month = dec,\n year = 1986,\n address = \"United States\",\n language = \"en\"\n}\n\n","author_short":["Shen, J M","Kriegstein, A R"],"key":"Shen1986-fm","id":"Shen1986-fm","bibbaseid":"shen-kriegstein-turtlehippocampalcortexcontainsdistinctcelltypesburstfiringneuronsandanepileptogenicsubfield-1986","role":"author","urls":{},"metadata":{"authorlinks":{}}},"bibtype":"article","biburl":"https://bibbase.org/f/EJMp3HRuxirjxpcXh/references.bib","dataSources":["sAFYeB74DpbdXM9NN","4zx9n2tbeLTix3Wxr","k3cdWrThyTh5o59Rm","hq9pebjzmsTuyxGGx","h8Atv2SAy4PmShg5j"],"keywords":[],"search_terms":["turtle","hippocampal","cortex","contains","distinct","cell","types","burst","firing","neurons","epileptogenic","subfield","shen","kriegstein"],"title":"Turtle hippocampal cortex contains distinct cell types, burst-firing neurons, and an epileptogenic subfield","year":1986}