Electrophysiology of Laminar Cortical Activity in the Common Marmoset

Summary

Custom-built micro-drives enable the sub-millimeter targeting of cortical recording sites with linear silicon arrays.

Abstract

The marmoset monkey provides an ideal model for examining laminar cortical circuits due to its smooth cortical surface, which facilitates recordings with linear arrays. The marmoset has recently grown in popularity due to its similar neural functional organization to other primates and its technical advantages for recording and imaging. However, neurophysiology in this model poses some unique challenges due to the small size and lack of gyri as anatomical landmarks. Using custom-built micro-drives, researchers can manipulate linear array placement to sub-millimeter precision and reliably record at the same retinotopically targeted location across recording days. This protocol describes the step-by-step construction of the micro-drive positioning system and the neurophysiological recording technique with silicon linear electrode arrays. With precise control of electrode placement across recording sessions, researchers can easily traverse the cortex to identify areas of interest based on their retinotopic organization and the tuning properties of the recorded neurons. Further, using this laminar array electrode system, it is possible to apply a current source density analysis (CSD) to determine the recording depth of individual neurons. This protocol also demonstrates examples of laminar recordings, including spike waveforms isolated in Kilosort, which span multiple channels on the arrays.

Introduction

The common marmoset (Callithrix jacchus) has quickly grown in popularity as a model to study brain function in recent years. This growing popularity is due to the accessibility of the marmoset's smooth cortex, the similarities in neural functional organization with humans and other primates, and the small size and fast breeding rate¹. As this model organism has grown in popularity, there has been rapid development in the neurophysiological techniques suited for use in the marmoset brain. Electrophysiology methods are widely used in neuroscience to study the activity of single neurons in the cortex of both rodents and primates, resu....

Protocol

The experimental procedures followed the National Institutes of Health Guide for the Care and Use of Laboratory Animals. The protocols for the experimental and behavioral procedures were approved by the University of Rochester Institutional Animal Care and Use Committee.

1. Construction of the micro-drive containing the electrode for recording (Figure 1)

NOTE: Custom-built X-Y stages holding multi-channel linear silicon a.......

Discussion

Several methods (e.g., chronic, semi-chronic, acute) are currently available for performing neurophysiology experiments in non-human primates. The common marmoset poses unique challenges for neurophysiology experiments due to its small size and lack of gyri as anatomical landmarks. This requires researchers to use neurophysiological landmarks such as the retinotopy and tuning properties of areas of interest to identify the recording targets. Therefore, when initially mapping out a cortical area, daily adjustments to the .......

Materials

Name	Company	Catalog Number	Comments
1/4 Hp burr drill bit	McMaster & Carr	Cat# 43035A32	Carbide Bur with 1/4" Shank Diameter, Rounded Cylinder Head, trade Number SC-1, single Cut(https://www.mcmaster.com/products/bur-bits/burs-7/?s=1%2F4%22+bur+bits)
1x1mm Crist Grid	Crist Instruments	1 mm x 1 mm Grid	https://www.cristinstrument.com/products/implant-intro/grids
91% isopropyl alcohol	Medline	N/A	https://www.medline.com/product/Medline-Isopropyl-Rubbing-Alcohol/Bulk-Alcohol/Z05-PF03807?question=91%25%20isopropyl%20alcohol
Acquisition Board	Open-Ephys	N/A	https://open-ephys.org/acquisition-system/eux9baf6a5s8tid06hk1mw5aafjdz1
Bacitracin Ointment	Medline: Cosette Pharmaceuticals Inc	N/A	https://www.medline.com/product/Bacitracin-Ointment/Antibiotics/Z05-PF86957?question=bacitr
Blunt straight Forceps	Medline	N/A	https://www.medline.com/category/Central-Sterile/Surgical-Instruments/Forceps/Z05-CA16_02_20/products
Bone wax	Medline	ETHW31G	https://www.medline.com/product/Ethicon-Bone-Wax/Bone-Wax/Z05-PF61528?question=bonewax
C&B Metabond Quick Adhesive Cement System	Parkell, Inc.	SKU: S380	https://www.parkell.com/C-B-Metabond-Quick-Adhesive-Cement-System
Clavamox	MWI Animal Health	N/A
Contact lens solution	Bausch and lomb		Various sources available
Custom Printed 3D printed parts	ProtoLab		https://marmolab.bcs.rochester.edu/resources.html
DB25-G2 25 Pin Male Plug Port Signal Connector	Various Sources	DB25-G2 25	DB25-G2 25 Pin Male Plug Port Signal 2 Row Terminal Breakout Board Screw Nut Connector
diamond saw attachement for dremmel	Dremmel	545 Diamond Wheel	https://www.dremel.com/us/en/p/545-26150545ab
Digitizing Head-stages	Intan	RHD 32channel (Part #C3314)	https://intantech.com/RHD_headstages.html?tabSelect=RHD32ch&yPos=120.80 000305175781
EDOT	Sigma Aldrich	Product # 483028	https://www.sigmaaldrich.com/US/en/product/aldrich/483028
Helping Hands	Harbor Freight	N/A	https://www.harborfreight.com/helping-hands-60501.html
Hook Electrical Clips	Various Sources	N/A	Hook test Cable wires
Interface Cables (RHD 3-ft (0.9 m) ultra thin SPI cable)	Intan	Part #C3213	https://intantech.com/RHD_SPI_cables.html
Lab jack	Various Sources	N/A	https://www.amazon.com/Stainless-Steel-Scissor-Stand-Platform/dp/B07T8FM85H/ref=asc_df_B07T8FM85H/?tag=&linkCode=df0&hvadid=366343 827267&hvpos=&hvnetw=g&hvrand =2036619536500717246&hvpone =&hvptwo=&hvqmt=&hvdev=c&hv dvcmdl=&hvlocint=&hvlocphy=900 5674&hvtargid=pla-795933567991& ref=&adgrpid=71496544770&th=1
Meloxicam	MWI Animal Health	N/A
Micro-drive	Crist Instrument	3-NRMD	https://www.cristinstrument.com/products/microdrives/miniature-microdrive-3-nrmd
Multi-channel linear silicon arrays with 64 channel connector	NeuroNexus	A1x32-5mm-25-177	https://www.neuronexus.com/products/electrode-arrays/up-to-10-mm-depth/
NanoZ Omentics Adapter- 32 Channel	NeuraLynx	ADPT-NZ-N2T-32	https://neuralynx.com/hardware/adpt-nz-n2t-32
NanoZ System	Plexon	NanoZ Impedence Tester	https://plexon.com/products/nanoz-impedance-tester/
Narishige Micromanipulator	Narishige	Stereotaxic Micromanipulator	https://usa.narishige-group.com/
Open-Ephys GUI	Open-Ephys		https://open-ephys.org/
Polyimide Tubing (OD(in): 0.021 / ID(in) 0.018 )	Various Sources (Chamfr)	Chamfr Cat#HPC01895	https://chamfr.com/sellers/teleflex-medical-oem-llc/
Primate Chair	Custom made by University of Rochester Machine Shop	Designs online	https://marmolab.bcs.rochester.edu/resources.html
Poly(sodium 4-styrenesulfonate) (PSS)	Sigma Aldrich	Product # 243051	https://www.sigmaaldrich.com/US/en/product/aldrich/243051
RHD USB Interface board	Intan	RHD2000 Evaluation Board Version 1.0	https://intantech.com/RHD_USB_interface_board.html
Silastic gel	World Precision Instuments	# KWIK-SIL	Low Toxicity Silicone Adhesive ((https://www.wpiinc.com/kwik-sil-low-toxicity-silicone-adhesive)
Slow release buprenorphine	Compounding Pharmacy
Stainless steel wire 36 gauge	McMaster & Carr	Cat# 6517K11	Round Bend-and-Stay Multipurpose 304 Stainless Steel Wire, Matte Finish, 1-Foot Long, 0.008" Diameter
Stanley 6-Piece Precision Screwdriver Set	Stanley	1.4mm flathead screwdriver	https://www.amazon.com/Stanley-Tools-6-Piece-Precision-Screwdriver/dp/B076621ZGC/ref=sr_1_3?crid=237VSK5FNFP9N&keywords= stanley+66-052&qid=1672764369&sprefix= stanley+66-052%2Caps%2C90&sr=8-3
Steel Screws	McMaster & Carr	type 00 stainless steel hex screws and 1/8” in length	https://www.mcmaster.com/
Steel Tube	McMaster & Carr	28 gauge stainless steel tubing	https://www.mcmaster.com/tubing/multipurpose-304-stainless-steel-6/id~0-055/
Superglue	Loctite	SuperGlue Gel Control	https://www.loctiteproducts.com/en/products/fix/super-glue/loctite_super_gluegelcontrol.html