Multifunctional fibers enable modulation of cortical and deep brain activity during cognitive behavior in macaques

Abstract

Recording and modulating neural activity in vivo enables investigations of the neurophysiology underlying behavior and disease. However, there is a dearth of translational tools for simultaneous recording and localized receptor-specific modulation. We address this limitation by translating multifunctional fiber neurotechnology previously only available for rodent studies to enable cortical and subcortical neural recording and modulation in macaques. We record single-neuron and broader oscillatory activity during intracranial GABA infusions in the premotor cortex and putamen. By applying state-space models to characterize changes in electrophysiology, we uncover that neural activity evoked by a working memory task is reshaped by even a modest local inhibition. The recordings provide detailed insight into the electrophysiological effect of neurotransmitter receptor modulation in both cortical and subcortical structures in an awake macaque. Our results demonstrate a first-time application of multifunctional fibers for causal studies of neuronal activity in behaving nonhuman primates and pave the way for clinical translation of fiber-based neurotechnology.

Fiber-based Probes for Electrophysiology, Photometry, Optical and Electrical Stimulation, Drug Delivery, and Fast-Scan Cyclic Voltammetry In Vivo

“…Although polymer waveguides have greater loss coefficients than silica fibers, the resulting attenuation is minimal at rodent-brain scales (6.1% for 5 mm) and is likely acceptable for studies in larger organisms such as non-human primates (58.8% for 7 cm, Figure 2a ). [ 34 ] Additionally, the substantially lower stiffness of polymer-based fibers compared to silica fibers is anticipated to improve mechanical compatibility with brain tissue.…”

An integrated microfluidic and fluorescence platform for probing in vivo neuropharmacology

“…Previous research endeavors have addressed this challenge by integrating electrophysiological recording with drug delivery systems, enabling simultaneous recording and chemical modulation of neural activity. For instance, multifunctional neural probes have been developed, incorporating materials such as tungsten (Garwood et al 2023, Ramadi et al 2018), poly(3,4-ethylenedioxythiophene):PSS(PEDOT:PSS) (Proctor et al 2018), and platinum electrodes into microfluidic systems (Shin et al 2017). These experiments provide important insight into how drugs alter activity of groups of local neurons.…”