Developmental Switch in Chandelier Cell GABA Polarity at the AIS

The apparent contradiction between chandelier cells being depolarizing vs inhibitory is resolved by developmental trajectory - GABA at AIS starts depolarizing but becomes hyperpolarizing over periadolescent period, though even depolarizing GABA inhibits AP initiation through shunting

{
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    {
      "n": 0,
      "doi": "10.3389/neuro.04.015.2009",
      "value": "Depolarized from rest in all cases",
      "method": "paired recordings from chandelier-pyramidal cell pairs",
      "metric": "GABA reversal potential at AIS relative to rest",
      "n_analyzed": null,
      "ci_or_error": null,
      "text_access": "abstract_only",
      "n_definition": "paired recordings",
      "scope_region": "somatosensory cortex upper layers",
      "study_system": "mouse somatosensory cortex, Nkx2.1Cre MADM mice",
      "taxonomic_level": "cell subtype",
      "scope_population": "chandelier cells",
      "value_source_sentence": "chandelier PSPs have in every case a reversal potential that is depolarized from rest.",
      "experimental_conditions": "perforated patch and cell-attached recordings"
    },
    {
      "n": 0,
      "doi": "10.1016/j.celrep.2017.06.030",
      "value": "Switches from depolarizing to hyperpolarizing over protracted periadolescent period",
      "method": "electrophysiology across development",
      "metric": "GABA reversal potential at AIS across development",
      "n_analyzed": null,
      "ci_or_error": null,
      "text_access": "abstract_only",
      "n_definition": "developmental age points",
      "scope_region": "prefrontal cortex",
      "study_system": "mouse prefrontal cortex pyramidal cells",
      "taxonomic_level": "cell subtype",
      "scope_population": "chandelier cells",
      "value_source_sentence": "GABAergic signaling at the AIS of prefrontal pyramidal cells, indeed, switches polarity from depolarizing to hyperpolarizing but does so over a protracted periadolescent period.",
      "experimental_conditions": "multiple developmental timepoints"
    },
    {
      "n": 0,
      "doi": "10.1523/jneurosci.0605-23.2023",
      "value": "Inhibitory via shunting across all periadolescent reversal potentials",
      "method": "electrophysiology with controlled GABA reversal",
      "metric": "Functional effect of GABA at AIS regardless of reversal potential",
      "n_analyzed": null,
      "ci_or_error": null,
      "text_access": "abstract_only",
      "n_definition": "recordings across reversal potentials",
      "scope_region": "prefrontal cortex L2/3",
      "study_system": "mouse PFC L2/3 pyramidal neurons",
      "taxonomic_level": "cell subtype",
      "scope_population": "pyramidal neurons receiving chandelier input",
      "value_source_sentence": "GABA at the axon initial segment inhibits action potential initiation in layer (L)2/3 pyramidal neurons in prefrontal cortex from mice of either sex across GABA reversal potentials observed in periadolescence.",
      "experimental_conditions": "varying GABA reversal potentials"
    }
  ],
  "comparison_id": "chandelier-polarity-development",
  "comparison_name": "Developmental Switch in Chandelier Cell GABA Polarity at the AIS",
  "comparison_type": "timeline",
  "what_it_reveals": "The apparent contradiction between chandelier cells being depolarizing vs inhibitory is resolved by developmental trajectory - GABA at AIS starts depolarizing but becomes hyperpolarizing over periadolescent period, though even depolarizing GABA inhibits AP initiation through shunting",
  "homogeneity_check": {
    "caveats": [
      "Different cortical regions (somatosensory vs prefrontal)",
      "Different developmental ages",
      "Different methodological approaches to measuring polarity"
    ],
    "n_definition_uniform": "false",
    "scope_region_uniform": "false",
    "taxonomic_level_uniform": "true",
    "scope_population_uniform": "true"
  },
  "suggested_plot_type": "timeline"
}

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  "paper:paper-2a56315e0967",
  "paper:paper-c803cdbd5cbd"
]

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