Learning and memory performance in mice lacking the GAL-R1 subtype of galanin receptor.
The neuropeptide galanin induces performance deficits in a wide range of cognitive tasks in rodents. Three G-protein-coupled galanin receptor subtypes, designated GAL-R1, GAL-R2 and GAL-R3, have been cloned. The present study examined the role of GAL-R1 in cognition by testing mice with a null mutation in Galr1 on several different types of learning and memory tasks. Assessments of general health, neurological reflexes, sensory abilities and motor functions were conducted as control measures. Mutant mice were unimpaired in social transmission of food preference and the Morris water maze. In tests of fear conditioning, mutant mice were unimpaired in a delay version of cued fear conditioning. However, mice homozygous for the null mutation were impaired in a trace version of cued fear conditioning. Mutant mice were unimpaired in contextual fear conditioning, whether training was by the delay or trace protocol. General health, neurological reflexes, sensory abilities and motor functions did not differ across genotypes, indicating that the trace fear conditioning deficit was not an artifact of procedural disabilities. The findings of normal performance on several cognitive tasks and a selective deficit in trace cued fear conditioning in homozygous GAL-R1 mutant mice are discussed in terms of hypothesized roles of the GAL-R1 subtype. The generally normal phenotype of GAL-R1 null mutants supports the use of this line for identification of the receptor subtypes that mediate the cognitive deficits produced by exogenous galanin.
Wrenn
Craige C
CC
Laboratory of Behavioural Neuroscience, National Institute of Mental Health, Bethesda, MD 20892-1375, USA. wrennc@intra.nimh.nih.gov
Kinney
Jefferson W
JW
Marriott
Lisa K
LK
Holmes
Andrew
A
Harris
Ashley P
AP
Saavedra
Maria C
MC
Starosta
Grzegorz
G
Innerfield
Caitlin E
CE
Jacoby
Arie S
AS
Shine
John
J
Iismaa
Tiina P
TP
Wenk
Gary L
GL
Crawley
Jacqueline N
JN
D000818:Animals; D003213:Conditioning, Psychological / Q000502:physiology; D005260:Female; D007858:Learning / Q000502:physiology; D008297:Male; D008568:Memory / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011597:Psychomotor Performance / Q000502:physiology; D044091:Receptor, Galanin, Type 1 / Q000172:deficiency* / Q000235:genetics
D044091:Receptor, Galanin, Type 1