Operant Protocols for Assessing the Cost-benefit Analysis During Reinforced Decision Making by Rodents

Summary

A cost-benefit analysis is a weighing-scale approach that the brain performs during the course of decision making. Here, we propose a protocol to train rats on an operant-based decision-making paradigm where rats choose higher rewards at the expense of waiting for 15 s to receive them.

Abstract

Reinforcement-guided decision making is the ability to choose between competing courses of action based on the relative value of the benefits and their consequences. This process is integral to the normal human behavior and has been shown to be disrupted by neurological and psychiatric disorders such as addiction, schizophrenia, and depression. Rodents have long been used to uncover the neurobiology of human cognition. To this end, several behavioral tasks have been developed; however, most are non-automated and are labor-intensive. The recent development of the open-source microcontroller has enabled researchers to automate operant-based tasks for assessing a variety of cognitive tasks, standardizing the stimulus presentation, improving the data recording and consequently, improving the research output. Here, we describe an automated delay-based reinforcement-guided decision-making task, using an operant T-maze controlled by custom-written software programs. Using these decision-making tasks, we show the changes in the local field potential activities in the anterior cingulate cortex of a rat whilst it performs a delay-based cost-and-benefit decision-making task.

Introduction

Decision making is the process of recognizing and selecting choices based on the values and preferences of the decision maker and the consequences of the selected action¹. Although decision making has been extensively studied in different fields (i.e., economics, psychology, and neuroscience), neural mechanisms underlying such cognitive abilities are not yet fully understood. Two subcategories of decision making are perceptual decision making and reinforcement-guided decision making. Though they incorporate considerable overlapping elements and concepts, perceptual decision making relies on the available sensory information

Protocol

All procedures explained here were approved and carried out in accordance with the Guide for the Care and Use of Laboratory Animals and were approved by the Florey Institute Animal Ethics Committee or the Neuroscience Research Center.

1. Housing, Handling, and Food Restriction

1. Use adult (normally 8 weeks old) male rats (any strains) and keep them in the room with a 12-h light/dark cycle.
2. Restrict their food access to encourage the animals to perform the task.
   Note: Housing the animals singularly is suggested, as it provides a better control of each one’s food intake.
3. On days 1 - 3, handle the ani....

Results

The data presented here is the recorded LFP from the left orbitofrontal cortex (OFC) and the anterior cingulate cortex (ACC) of six male Wistar rats using bipolar electrodes (of PFA-coated stainless steel). Table 1 shows the behavioral acquisition length for each training stage. The coordinates for the target locations were determined from a rat brain atlas⁹ and are as follows: for the AAC, 1.2 mm anterior to the bregma, 0.8 mm lateral to the midli.......

Discussion

Rodents have long been used in neuroscientific studies that deal with different topics, from cognitive abilities such as learning and memory^2,14 and reinforced behavior^7,15,16 to the central control of organs^17,18 and neuropharmacology^19,20. The proposed .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
T-maze			Self made
Dustless Precision Sugar Pellets	TSE Systems Intl. Group	F0023	45 mg, Sucrose
Ketamine Hydrochloride Injection, USP	Sigma-Aldrich	6740-87-0
Xylazine	Sigma-Aldrich	7361-61-7
stereotaxic device	Stoelting
Isofluran	Santa Cruz Biotechnology	sc-363629Rx
PFA-coated stainless-steel wires	A-M systems
acrylic cement	Vertex, MA, USA
(wooden or PVC (polyvinyl chloride)-made)	local suppliers
Mini-Fit Power Connector	Molex	15243048
ethannol 70%	Local suppliers
buprenorphine	diamondback drugs
Arduino UNO	Arduino		https://www.arduino.cc/
Infrared emitting diode	Sharp	GL480E00000F	http://www.sharp-world.com/
Chronux Toolbox			Chronux.org
Arduino codes			https://github.com/dechuans/arduino-maze