FARESHARE: An open-source apparatus for assessing drinking microstructure in socially housed rats

Abstract

Social factors have been shown to play a significant and lasting role in alcohol consumption. Studying the role of social context on alcohol drinking is important to understand the factors that contribute to the initiation or maintenance of casual and problematic alcohol use, as well as those that may be protective. A substantial body of preclinical research has shown that social environment such as housing conditions and social rank plays an important role in alcohol consumption and preference, though the extent of these effects have been obfuscated by methodological differences and technical challenges. Robust individual differences in alcohol intake in socially housed animals are difficult to track when animals share a common fluid source. Commercial solutions are prohibitively expensive and are limited by proprietary software and hardware (including caging systems). Here we describe FARESHARE, an affordable, open-source solution for tracking fluid consumption in socially housed rats. The device uses RFID and custom hardware to individually measure and record each rat’s fluid consumption and licking microstructure. Each bout is also timestamped such that the circadian effects of drinking behaviour may be analysed. We provide a validation showing the operation of the device in a two-bottle-choice alcohol-drinking paradigm over a nine-day period in four group-housed female rats. We show that FARESHARE is able to capture traditional measures such as daily intake and preference, as well as circadian effects, microstructure, and individual variations in drinking.

Effects of social housing on alcohol intake in mice depend on the non-social environment

“…Efforts to allow testing alcohol drinking in socially housed animals via various other methods are underway in other research groups [reviewed in Ryabinin and Walcott (2018) ]. While many of these methods have their own advantages, we note that currently they are based on either measuring proximity to the drinking spout ( Logue et al, 2014 ; Varlinskaya et al, 2015 ) or registering licking behavior ( Holgate et al, 2017 ; Stefaniuk et al, 2017 ; Frie and Khokhar, 2024 ). Although applying varied methods to assess behaviors has advantages over a single method, our studies in HM2 cages indicate that results from measures of approach to the fluid do not always coincide with measures of intake.…”

A novel mouse home cage lickometer system reveals sex- and housing-based influences on alcohol drinking

“…However, these systems are costly and require specialized housing. Tracking multiple animals in a cage can be performed with implanted radio-frequency identification (RFID) tags, which have been utilized in commercially available systems and by recently developed open-source behavioral devices to identify group-housed mice with video-assisted tracking in an arena (Peleh et al, 2019), mice in specialized housing (Wong et al, 2023), and rats during home cage drinking (Frie & Khokhar, 2024).…”

Modelling alcohol consumption in rodents using two-bottle choice home cage drinking and optional lickometry-based microstructural analysis

“…This system was subsequently adapted by a separate group for use in rats 22 . In the years since, variations on this theme have been used to develop similar systems contained within custom rodent housing 23 , that allow for lick detection of individual socially housed animals 24,25 , and that capture both feeding and drinking behavior 26 . Among these, LIQ HD 27 has garnered significant attention for offering a system for use in mice that parallels the ease of implementation and affordability of the system developed by Godnyuck et al 21 but uses a capacitance sensor, which the authors demonstrate affords greater precision over photobeam lick detection.…”