Alcohol consumption in domestic and wild rats

Abstract

Experimental attempts to establish in laboratory rats a behavior pattern analogous to human alcoholism have generally reaped negative results. Temporary increases in alcohol consumption have been achieved repeatedly (Senter & Sinclair, 1967;Senter, Smith, & Lewin, 1967;Myers, 1966), but the establishment of chroniC, autonomous, maladaptive alcohol consumption is so rare that McConnell & Clay (1963) have questioned whether mammals lower than man are susceptible to the development of such behavior patterns. An exception to this trend has been reported by Richter (1957). While this researcher reported repeated failure to addict domestic laboratory rats, he succeeded in "addicting two fierce, aggressive wild rats trapped from the streets. This was done by restricting fluid intakes to a 20% solution of alcohol over a period of six months. When given a choice of food, water and a 20% solution of alcohol, these rats gradually ate less food, drank less plain water, and more alcohol. As a result they progressively lost weight and finally died" (p. 218). The present research was undertaken to investigate more systematically the observation made by Richter. MethodTwenty wild pack rats (Genus Neotoma), captured in Arizona, and 16 domestic hooded rats were continuously exposed to standard laboratory rat chow and a 20% (V IV) alcohol solution for 20 weeks. Subsequent to this exposure period, both groups were given rat chow, a 20% alcohol solution, and water for nine weeks. Consumption of alcohol solution was recorded daily throughout the 20 week exposure period and the nine week choice period. Weekly mean consumption of alcohol solution in ml for each S was established for data analysis.

Domestication.

“…In the second kind, wildness is assumed to be general with little regard for phylogenetic similarity between the captive and domestic rats. Thus psychologists (Eimer & Senter, 1968;Powell & Morris, 1968) have compared behaviors of wild and domestic rats across families. These comparisons tell little of domestication in laboratory rats because there is no reason to believe that the domesticated version of the cotton rat or the pack rat (neither of which is available) would resemble the domestic Norway rat.…”

Reply to Boice and Aspey

“…The main points of the Boice and Aspey criticism of these writers' earlier publication (Eimer & Senter, 1968) seem to be: (I) that the comparison of the alcohol consumption pattern of domestic Norway rats (Rattus norvegicus) with that of wild pack rats (Neotoma cinerea) constitutes an inappropriate experimental arrangement because the comparison is across zoological genera and (2) that N. cinerea is an other than ideal animal to use to reexamine the conditions which Richter (1957) reported as producing alcohol "addiction" in wild R. norvegicus. Any reasonable scientist must concur.…”