Reactivity to novelty in cognitively-impaired and cognitively-unimpaired aged rats and young rats

Rowe, Wayne B.; Spreekmeester, Emma; Meaney, Michael J.; Quirion, Rémi; Rochford, Joseph

doi:10.1016/s0306-4522(97)00464-8

Cited by 100 publications

(77 citation statements)

References 27 publications

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“…Since previous studies showed no significant age-related differences in withdrawal latency to hot temperatures 32 and mechanical stimuli 42 in adult rats, the end point of shamoperated rats was determined at 5 weeks postoperatively. In addition, as part of unpublished experiments, we have examined 3 sham-operated rats for behavioral but mainly for possible age-related changes in histological data at 30 weeks postoperatively.…”

Section: Discussionmentioning

confidence: 99%

Long-term follow-up of peptidergic and nonpeptidergic reinnervation of the epidermis following sciatic nerve reconstruction in rats

Kambiz

Duraku

Baas

et al. 2015

JNS

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OBJECT Peripheral nerve injuries are a commonly encountered clinical problem and often result in long-term functional deficits. The current gold standard for transected nerves is an end-to-end reconstruction, which results in the intermittent appearance of neuropathic pain. METHODS To improve our understanding of the relation between this type of reconstruction and neuropathic pain, the authors transected and immediately end-to-end reconstructed the sciatic nerve in rats. The effect of this procedure on neuropathic pain, as measured by thermal and mechanical hypersensitivity at 4 different time points (5, 10, 20, and 30 weeks), was related to the density of peptidergic and nonpeptidergic fiber innervation in the glabrous skin of rats' hind paws. RESULTS Thermal hypersensitivity occurring 20 weeks after reconstruction was accompanied by a significant increase in peptidergic epidermal fibers. However, the lesion-induced reduction in the density of nonpeptidergic epidermal fibers remained decreased at all experimental time points. Moreover, temporal collateral sprouting by undamaged saphenous nerve was visualized using the recently revised Evans blue extravasation technique. Strikingly, as the sciatic nerve repopulated rats' hind paw, the saphenous nerve withdrew to its original territory. CONCLUSIONS The authors conclude that the transient thermal hypersensitivity is related to increased density of epidermal peptidergic fibers, which mainly originate from regenerating fibers. Furthermore, a changed composition in the peptidergic and nonpeptidergic epidermal fibers is demonstrated following end-to-end reconstruction of the sciatic nerve.

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Section: Discussionmentioning

confidence: 99%

Long-term follow-up of peptidergic and nonpeptidergic reinnervation of the epidermis following sciatic nerve reconstruction in rats

Kambiz

Duraku

Baas

et al. 2015

JNS

View full text Add to dashboard Cite

show abstract

“…For example, studies have suggested that when aging animals interact within a more complex environment, it increases dendritic complexity and cortical thickness, and promotes cognitive abilities (Connor, Melone, Yuen, & Diamond, 1981;Kempermann, Kuhn, & Gage, 1997). Older animals who are more engaged by novel stimuli also tend to exhibit greater preservation of cognitive performance (Rowe, Spreekmeester, Meaney, Quirion, & Rochford, 1998). In a mouse model of Alzheimer's disease, exposure of transgenic mice to an enriched environment has been associated with reduced Aβ levels and amyloid deposition, two components of the neurodegenerative process (Lazarov et al, 2005).…”

Section: Discussionmentioning

confidence: 99%

Cognitive status impacts age-related changes in attention to novel and target events in normal adults.

et al. 2007

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This study investigated the relationship between the cognitive status of normal adults and agerelated changes in attention to novel and target events. Old, middle-aged, and young subjects, divided into cognitively high and cognitively average performing groups, viewed repetitive standard stimuli, infrequent target stimuli, and unique novel visual stimuli. Subjects controlled viewing duration by a button press that led to the onset of the next stimulus. They also responded to targets by pressing a foot pedal. The amount of time spent looking at different kinds of stimuli served as a measure of visual attention and exploratory activity. Cognitively high performers spent more time viewing novel stimuli than cognitively average performers. The magnitude of the difference between cognitively high and cognitively average performing groups was largest

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“…Young and aged rats were tested in the Morris water maze as described previously (Rowe et al, 1998). The maze consisted of a 1.6-m-diameter circular pool filled to within 15 cm of the rim with water (22°C) made opaque by the addition of nontoxic white latex paint (Createx Colors, East Granby, C T).…”

Section: Methodsmentioning

confidence: 99%

Theta-Frequency Synaptic Potentiation in CA1In VitroDistinguishes Cognitively Impaired from Unimpaired Aged Fischer 344 Rats

et al. 2002

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Hippocampal-dependent learning and memory deficits have been well documented in aging rodents. The results of several recent studies have suggested that these deficits arise from weakened synaptic plasticity within the hippocampus. In the present study, we examined the relationship between hippocampal long-term potentiation (LTP) in vitro and spatial learning in aged (24-26 months) Fischer 344 rats. We found that LTP induced in the CA1 region using theta-frequency stimulation (5 Hz) is selectively impaired in slices from a subpopulation of aged rats that had shown poor spatial learning in the Morris water maze. LTP at 5 Hz in aged rats that did not show learning deficits was similar to that seen in young (4-6 months) controls. We also found that 5 Hz LTP amplitude strongly correlated with individual learning performance among aged rats. The difference in 5 Hz LTP magnitude among aged rats was not attributable to an altered response to 5 Hz stimulation or to differences in the NMDA receptormediated field EPSP. In addition, no performance-related differences in LTP were seen when LTP was induced with 30 or 70 Hz stimulation protocols. Finally, both 5 Hz LTP and spatial learning in learning-impaired rats were enhanced with the selective muscarinic M 2 antagonist ]benzodiazepin-6-one). These findings reinforce the idea that distinct types of hippocampal LTP offer mechanistic insight into age-associated cognitive decline.

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Reactivity to novelty in cognitively-impaired and cognitively-unimpaired aged rats and young rats

Cited by 100 publications

References 27 publications

Long-term follow-up of peptidergic and nonpeptidergic reinnervation of the epidermis following sciatic nerve reconstruction in rats

Long-term follow-up of peptidergic and nonpeptidergic reinnervation of the epidermis following sciatic nerve reconstruction in rats

Cognitive status impacts age-related changes in attention to novel and target events in normal adults.

Theta-Frequency Synaptic Potentiation in CA1In VitroDistinguishes Cognitively Impaired from Unimpaired Aged Fischer 344 Rats

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