Age-related differences in appetitive trace conditioning and novel object recognition procedures
Marshall, Hayley J
Pezze, Marie A
Fone, Kevin F
Cassaday, Helen J
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Appetitive trace conditioning (TC) was examined over 6 months in younger-adult (2-8 months) and middle-aged (12-18 months) male Wistar RccHan rats to test for early age-related impairment in working memory. Novel object recognition (NOR) was included as a comparison task to provide a positive control in the event that the expected impairment in TC was not demonstrated. The results showed that TC improved at both ages at the 2s but not at the 10s trace interval. There was, however, evidence for reduced improvement from one day to the next in the middle-aged cohort tested with the 2s trace conditioned stimulus. Moreover, within the 10s trace, responding progressively distributed later in the trace interval, in the younger-adult but not the middle-aged cohort. Middle-aged rats showed NOR discriminative impairment at a 24h but not at a 10 min retention interval. Object exploration was overall reduced in middle-aged rats and further reduced longitudinally. At the end of the study, assessing neurochemistry by HPLC-ED showed reduced 5-HIAA/5-HT in the dorsal striatum of the middle-aged rats and some correlations between striatal 5-HIAA/5-HT and activity parameters. Overall the results suggest that, taken in isolation, age-related impairments may be overcome by experience. This recovery in performance was seen despite the drop in activity levels in older animals, which might be expected to contribute to cognitive decline.
- psychobiology; memory
- trace conditioning; rat medial prefrontal cortex; dorsal striatum; nucleus accumbens; HPLC-ED
- Biological Sciences
- Biological Sciences::Psychology::Psychobiology
- Q Science::QP Physiology
- University of Nottingham, UK Campus
Data typeSPSS data set of behavioural observations: Appetitive Trace Conditioning (Nose Pokes); Novel Objection Recognition (Time (sec) exploring Familiar & Novel Objects); High Performance Liquid Chromatography (HPLC) to assess neuropharmacological substrates within three brain regions (mPFC, dorsal and ventral striatum (NAc)).
- Biotechnology & biological Sciences Research Council
Data collection methodAppetitive trace conditioning protocol; Novel Object recognition Protocol; Brain regions were sampled for assay based on the Rat Brain Atlas, Paxinos and Watson (1998).
Legal and ethical issuesRegulated procedures were carried out in accordance with the principles of laboratory animal care, specifically the United Kingdom (UK) Animals Scientific Procedures Act 1986, Project Licence number PPL 40/3716, with the approval of the University of Nottingham Animal Welfare and Ethical Review Body (AWERB) committee and following the ARRIVE guidelines.
- University of Nottingham