Target Validation Electrophysiology Core

Overview of Services

Below is a list of existing capabilities and techniques in which we are experienced.  Of course, we are willing to expand our capabilities and attempt new techniques if needed!  Click here to submit a request for TVEC services.

 

Electrophysiological measures*

  • whole cell, cell-attached, and field recordings
  • passive and active membrane properties
  • excitatory or inhibitory transmission

Acute brain slice preparations

  • dorsal and ventral hippocampus
  • nucleus accumbens
  • basolateral amygdala
  • ventral midbrain
  • prefrontal cortex

Complementary assays and tools

In vivo ethanol exposure:

  • chambers for ethanol vapor exposure
  • 2BC, DID, and operant self-administration

Cell-type and circuit identification:

  • Drd1a-tdTomato mice and Pitx3-egfp transgenic mice
  • CtB-Alexa Fluor for retrograde labeling of neurons

Cell-type and circuit manipulation:

  • optogenetic stimulation or silencing ex vivo
  • optogenetic silencing in vivo in MedAssociates chambers
  • chemogenetic silencing

*Expanded Description of Electrophysiological Measures

In general, numbers (1) - (6) of the following measures can be collected from GABAergic, glutamatergic,
or dopaminergic neurons, and measure (7) also can be collected from some types of neurons (e.g., dopamine neurons):

(1)  membrane properties and excitability

(2) spontaneous and miniature AMPAR-mediated excitatory postsynaptic currents (sEPSCs and mEPSCs)

(3) ratio of evoked AMPAR-mediated EPSC to evoked NMDAR-mediated EPSC (AMPA/NMDA)

(4) rectification index from current-voltage relationship for evoked AMPAR-mediated EPSCs – indicative of
calcium-permeable AMPAR contribution to AMPAR-mediated EPSCs

(5) spontaneous and miniature GABAAR-mediated inhibitory postsynaptic currents (sIPSCs and mIPSCs

(6) synaptic plasticity – long term depression or potentiation of evoked events

(7) spontaneous action potential firing

If experimental manipulations alter measures (2) or (5), then measure (8), paired-pulse ratio of evoked currents, can be evaluated as an indicator for differences in pre-synaptic neurotransmitter release probability. An effect on measure (3) can be considered alongside effects on measures (2) and (4) and further investigated with measure (9), input-output curve for evoked NMDAR-mediated EPSCs. In addition, measures (1) and (5) - (9) are responsive to acute ethanol application and therefore also can be evaluated for interactions between experimental manipulations and responses to ethanol ex vivo.

See for examples:

Maiya R, Mangieri RA, Morrisett RA, Heberlein U, Messing RO (2015). A Selective Role for Lmo4 in Cue-Reward Learning. J Neurosci 35: 9638–9647.

Mangieri RA, Maier EY, Buske TR, Lasek AW, Morrisett RA (2017). Anaplastic Lymphoma Kinase Is a Regulator of Alcohol Consumption and Excitatory Synaptic Plasticity in the Nucleus Accumbens Shell. Front Pharmacol 8: 1–13.

Renteria R, Buske TR, Morrisett RA (2018). Long-term subregion-specific encoding of enhanced ethanol intake by D1DR medium spiny neurons of the nucleus accumbens. Addict Biol 23(2):689-698.

Renteria R, Maier EY, Buske TR, Morrisett RA (2017). Selective Alterations of NMDAR Function and Plasticity in D1 and D2 Medium Spiny Neurons in the Nucleus Accumbens Shell Following Chronic Intermittent Ethanol Exposure. Neuropharmacology 112(Pt A): 164-171.

Theile JW, Morikawa H, Gonzales RA, Morrisett RA (2008). Ethanol enhances GABAergic transmission onto dopamine neurons in the ventral tegmental area of the rat. Alcohol Clin Exp Res 32: 1040–8.

Theile JW, Morikawa H, Gonzales RA, Morrisett RA (2011). GABAergic transmission modulates ethanol excitation of ventral tegmental area dopamine neurons. Neuroscience 172: 94–103.