Non-ocular circadian oscillators and photoreceptors modulate long term memory formation in Aplysia

Lyons, Lisa C., Rawashdeh, Oliver and Eskin, Arnold (2006) Non-ocular circadian oscillators and photoreceptors modulate long term memory formation in Aplysia. Journal of Biological Rhythms, 21 4: 245-255. doi:10.1177/0748730406289890

Author Lyons, Lisa C.
Rawashdeh, Oliver
Eskin, Arnold
Title Non-ocular circadian oscillators and photoreceptors modulate long term memory formation in Aplysia
Journal name Journal of Biological Rhythms   Check publisher's open access policy
ISSN 0748-7304
Publication date 2006
Sub-type Article (original research)
DOI 10.1177/0748730406289890
Volume 21
Issue 4
Start page 245
End page 255
Total pages 11
Language eng
Subject 1101 Medical Biochemistry and Metabolomics
1314 Physiology
2737 Physiology (medical)
Abstract In Aplysia californica, memory formation for long-term sensitization (LTS) and for a more complex type of associative learning, learning that food is inedible (LFI), is modulated by a circadian clock. For both types of learning, formation of long-term memory occurs during the day and significantly less during the night. Aplysia eyes contain a well-characterized circadian oscillator that is strongly coupled to the locomotor activity rhythm. Thus, the authors hypothesized that the ocular circadian oscillator was responsible for the circadian modulation of LFI and LTS. To test this hypothesis, they investigated whether the eyes were necessary for circadian modulation of LFI and LTS. Eyeless animals trained during the subjective day and tested 24 h later demonstrated robust long-term memory for both LFI and LTS, while eyeless animals trained and tested during the subjective night showed little or no memory for LFI or LTS. The amplitude of the rhythm of modulation in eyeless animals was similar to that of intact Aplysia, suggesting that extraocular circadian oscillators were mainly responsible for the circadian rhythms in long-term memory formation. Next, the authors investigated whether the eyes played a role in photic entrainment for circadian regulation of long-term memory formation. Eyeless animals were exposed to a reversed LD cycle for 7 days and then trained and tested for long-term memory using the LFI paradigm. Eyeless Aplysia formed significant long-term memory when trained during the projected shifted day but not during the projected shifted night. Thus, the extraocular circadian oscillator responsible for the rhythmic modulation of long-term memory formation can be entrained by extraocular photoreceptors.
Keyword Aplysia
Biological clock
Circadian rhythm
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: Scopus Import
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 15 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 15 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Wed, 16 Mar 2016, 08:55:39 EST by Oliver Rawashdeh