Sensory Gating, Anxiety, Seizures, and Pain Neuronal Networks Laboratory University of Nottingham Medical School Neuronal Networks Laboratory Using Plexon at Nottingham: Sensory Gating, Anxiety, Seizures, and Pain Dr Rob Mason School of Biomedical Sciences University of Nottingham Medical School

Neuronal Networks Laboratory Talk Format Brief overview of what we have been studying using Plexon system(s) at Nottingham Indicate on route some hardware developments & signal processing / analysis approaches we use schizophrenia – sensory gating epilepsy anxiety pain

Multiple Electrode Recordings in vivo simultaneous multichannel spike & field potential recording 64-channel MAP system 32-channel MAP system – with CinePlex for behavioural studies 64-channel Recorder system 16-channel Recorder system used MAP & Recorder for in vitro MEA studies with brain slices & neuronal cultures

LAB TEAM epilepsy Ben Coomber [Dr Mike O’Donoghue] Clare Roe Neuronal Networks Laboratory LAB TEAM epilepsy Ben Coomber [Dr Mike O’Donoghue] Clare Roe schizophrenia Dr Jill Suckling [Prof CA Marsden] Dr Dissanayake anxiety Dr Carl Stevenson [Prof CA Marsden] pain Dr Steve Elmes [Dr V Chapman] rodent USVs Beth Tunstall [Dr S Beckett] data analysis Margarita Zachariou [Dr S Coombes / Dr M Owen] [Mathematics Dept] Dr David Halliday (University of York) Prof D Auer (fMRI / phMRI)

LAB EXPERIMENTAL DIRECTIONS medial Pre-Frontal Cortex mPFCx interconnectivity & functional context – in vivo studies maternal separation - depression circadian - affective states sensory gating - schizophrenia - epilepsy USVs medial Pre-Frontal Cortex Amygdala nucleus Accumbens Hippocampus SCN Contralateral mPFC VTA - drugs of abuse PVt

Systemic pharmacological manipulation Neuronal Networks Laboratory Dual site recordings VTA - mPFC hippocampus - mPFC amygdala - mPFC mPFC - mPFC Systemic pharmacological manipulation Local pharmacological manipulation “injec-trode” integrated microiontophoresis with recording array Electrical stimulation Independent electrode array microdrive Anaesthetised & awake-behaving preparations

Project #1: Schizophrenia Neuronal Networks Laboratory University of Nottingham Medical School Neuronal Networks Laboratory Project #1: Schizophrenia auditory-evoked sensory gating effects of PCP / ketamine - model effects of social isolation - model

Schizophrenia - VTA/mPFCx dual-site recordings Prussian Blue reaction - locate recording site(s) - histology ventral tegmental area - VTA medial prefrontal cortex - mPFC

Dual site recording: pre-frontal cortical / VTA recording multiple single-units & LFPs 1 mV 5 s VTA cells PFC LFP 1 8 7 Neurone # Matlab scripts for off-line characterisation unit spike waveforms & LFPs

Local application of drugs – “injec-trode” Explore connectivity between PFC and VTA - e.g. local application of drug (e.g. glutamate) to VTA to drive mPFC Local application of drugs – “injec-trode” 10s Extra-VTA PFC Extra-VTA LFP PFC LFP 50 nl Glutamate (100 mM) Electrode headstage Tubing attached to Hamilton syringe Electrode tips Cannula tip

Sensory gating in hippocampus: A model for schizophrenia ? Neuronal Networks Laboratory Sensory gating in hippocampus: A model for schizophrenia ? Sensory gating: mechanism(s) by which irrelevant sensory information is filtered – enables efficient information processing Auditory Conditioning-Test paradigm: measures reduction in auditory-evoked response produced by Test stimulus following a Conditioning stimulus Stimuli: 3kHz sine-wave / 10ms duration / presented 500ms apart / 80-90dB human P50 wave = rat N40 component Gating absent in - schizophrenic patients (& near family members) - normal human volunteers given PCP / amphetamine - rats given PCP / amphetamine

Hippocampal CA3 - auditory-evoked unit & LFP activity 1s LFP2 averaged 128 trials Units LFPs event tone - 128 - 1 Trial # s Cs Ts mV N40 Averaged LFP T/C ratio = 50%

Single-unit PSTHs ‘ rasters histograms - gating rats dentate gyrus CA3 region Single-unit PSTHs ‘ rasters histograms - gating rats Unit 1 Unit 2 Unit 3 Unit 4 Spike raster PSTH LFP LFP trial raster

Hippocampal CA3 auditory-evoked unit & LFP activity Effects of PCP (1mg/kg i.p.)  attenuates/abolishes sensory gating Basal [128 trials] T/C ratio = 32% 45mins after PCP T/C ratio = 66% 1 Trail # 128

University of Nottingham Medical School Neuronal Networks Laboratory Project #2: Epilepsy kainate-induced epileptiform activity – TLE functional network interactions - hippocampus  mPFC electrical stimulation – perforant pathway role of endocannibnoid system – CB1R pharmacology

Kainate-induced epileptiform activity – dual recording hippocampus & mPFC HippL HippM Basal firing KA-induced firing (10mg kg-1, i.p.) 2s hippocampus mPFC

Hippocampal-mPFC – functional connectivity Burst analysis – Synchrony index - Cross-correlation – coherence - PDC mPFC Hipp HIPP Ref unit mPFC Hippocampus unit 3H unit 1H unit 2H

PDC Analysis – Unit populations Identify direction of activity between hippocampus and mPFC - PDC applied: technique with potential to reveal the neuronal ensemble drive direction. Note: the magnitude of the classical coherence gives no information about directional connectivity, but its phase may do so. KA

PDC Analysis – LFPs Representative PDC plot between LFPs recorded from 3 electrodes in both mPFC (AD01-08) hippocampus (AD10 to AD16 = medial to lateral electrodes). TIME FRAME # Hippocampus mPFC Red boxes highlight PDC between brain regions – suggesting the predominant flow is from mPFC to hippocampus Green boxes highlight that the predominant flow within hippocampus is from lateral to medial.

LFPanalyser suite 2006 – custom Matlab script Basal (pre-KA challenge) - hippocampus

45min post-KA - hippocampus LFPanalyser suite 2006

LFPanalyser suite 2006

% Power Distribution Basal 45min Post-KA LFPanalyser suite 2006

Project #3: Nociception & pain management Neuronal Networks Laboratory University of Nottingham Medical School Neuronal Networks Laboratory Project #3: Nociception & pain management dual spinal cord / supraspinal recording Role of endocannabinoid system in normal physiology and pain (e.g. neuropathic) states

Mechanically-evoked response in somatosensory thalamus (VPM) innocuous (7g) stimulation noxious (65g) stimulation

Project #4: Affective state Neuronal Networks Laboratory University of Nottingham Medical School Neuronal Networks Laboratory Project #4: Affective state Cortico-limibic network interactions anxiety effects of maternal separation pharmacologically-induced (e.g. FG-7142) anxiety behavioural sequalae rodent ultrasound vocalisations

nucleus accumbens – mPFC Role of nuc accumbens in USV-mediated Behaviours nucleus accumbens / basolateral amygdala - mPFCx functional connectivity nucleus accumbens – mPFC Rat ultrasound vocalisations (USVs) & affective state Neuronal Networks Laboratory 50kHz 22kHz Time (s) Frequency (kHz) ~22 kHz calls - aversive stimuli (call Type G) ~50 kHz calls - rewarding stimuli (Types A-F)

Combined unit / LFP with USV / behavioural recording USV call start time unit activity - nuc accumbens USV Recorder input Behavioural data Local Field Potential (LFP) Spectrogram of specific calls [AviSoft]

Multiple Electrode Recordings in vivo simultaneous multichannel spike / field potential / behavioural recording Video camera CinePlex system

Behavioural Electrophysiology II Neuronal Networks Laboratory Behavioural Electrophysiology II Circular arena recording using CinePlex Movie - rat HopScotch: 8-microwire array in nuc. accumbens - 6 weeks post implant Recorded video Neural data

University of Nottingham Medical School Neuronal Networks Laboratory That’s all folks Lab web site www.nottingham.ac.uk/neuronal-networks