scholarly journals Unraveling the complexities of circadian and sleep interactions with memory formation through invertebrate research

MicroRNA ◽  
2020 ◽  
Vol 09 ◽  
Author(s):  
Sadniman Rahman ◽  
Chaity Modak ◽  
Mousumi Akter ◽  
Mohammad Shamimul Alam

Background: Learning and memory is basic aspects in neurogenetics as most of the neurological disorders start with dementia or memory loss. Several genes associated with memory formation have been discovered. MicroRNA genes miR-1000 and miR-375 were reported to be associated with neural integration and glucose homeostasis in some insects and vertebrates. However, neuronal function of these genes is yet to be established in D. melanogaster. Objective: Possible role of miR-1000 and miR-375 in learning and memory formation in this fly has been explored in the present study. Methods: Both appetitive and aversive olfactory conditional learning were tested in the miR-1000 and miR-375 knockout (KO) strains and compared with wild one. Five days old third instar larvae were trained by allowing them to be associated with an odor with reward (fructose) or punishment (salt). Then, the larvae were tested to calculate their preferences to the odor trained with. Learning index (LI) values and larval locomotion speed were calculated for all strains. Results: No significant difference was observed for larval locomotion speed in mutant strains. Knockout strain of miR-1000 showed significant deficiency in both appetitive and aversive memory formation whereas miR-375 KO strain showed a significantly lower response only in appetitive one. Conclusion: The results of the present study indicate important role played by these two genes in forming short-term memory in D. melanogaster.


2022 ◽  
Vol 119 (3) ◽  
pp. e2107661119
Author(s):  
William P. Dempsey ◽  
Zhuowei Du ◽  
Anna Nadtochiy ◽  
Colton D. Smith ◽  
Karl Czajkowski ◽  
...  

Defining the structural and functional changes in the nervous system underlying learning and memory represents a major challenge for modern neuroscience. Although changes in neuronal activity following memory formation have been studied [B. F. Grewe et al., Nature 543, 670–675 (2017); M. T. Rogan, U. V. Stäubli, J. E. LeDoux, Nature 390, 604–607 (1997)], the underlying structural changes at the synapse level remain poorly understood. Here, we capture synaptic changes in the midlarval zebrafish brain that occur during associative memory formation by imaging excitatory synapses labeled with recombinant probes using selective plane illumination microscopy. Imaging the same subjects before and after classical conditioning at single-synapse resolution provides an unbiased mapping of synaptic changes accompanying memory formation. In control animals and animals that failed to learn the task, there were no significant changes in the spatial patterns of synapses in the pallium, which contains the equivalent of the mammalian amygdala and is essential for associative learning in teleost fish [M. Portavella, J. P. Vargas, B. Torres, C. Salas, Brain Res. Bull. 57, 397–399 (2002)]. In zebrafish that formed memories, we saw a dramatic increase in the number of synapses in the ventrolateral pallium, which contains neurons active during memory formation and retrieval. Concurrently, synapse loss predominated in the dorsomedial pallium. Surprisingly, we did not observe significant changes in the intensity of synaptic labeling, a proxy for synaptic strength, with memory formation in any region of the pallium. Our results suggest that memory formation due to classical conditioning is associated with reciprocal changes in synapse numbers in the pallium.


1998 ◽  
Vol 23 (1) ◽  
pp. 65-72 ◽  
Author(s):  
John W Newcomer ◽  
Suzanne Craft ◽  
Kelly Askins ◽  
Tamara Hershey ◽  
Mark E Bardgett ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-20 ◽  
Author(s):  
Fenxia Yan ◽  
Zilong Gao ◽  
Pin Chen ◽  
Li Huang ◽  
Dangui Wang ◽  
...  

Neural plasticity is associated with memory formation. The coordinated refinement and interaction between cortical glutamatergic and GABAergic neurons remain elusive in associative memory, which we examine in a mouse model of associative learning. In the mice that show odorant-induced whisker motion after pairing whisker and odor stimulations, the barrel cortical glutamatergic and GABAergic neurons are recruited to encode the newly learnt odor signal alongside the innate whisker signal. These glutamatergic neurons are functionally upregulated, and GABAergic neurons are refined in a homeostatic manner. The mutual innervations between these glutamatergic and GABAergic neurons are upregulated. The analyses by high throughput sequencing show that certain microRNAs related to regulating synapses and neurons are involved in this cross-modal reflex. Thus, the coactivation of the sensory cortices through epigenetic processes recruits their glutamatergic and GABAergic neurons to be the associative memory cells as well as drive their coordinated refinements toward the optimal state for the storage of the associated signals.


PLoS ONE ◽  
2011 ◽  
Vol 6 (2) ◽  
pp. e16695 ◽  
Author(s):  
Katharina A. Bialleck ◽  
Hans-Peter Schaal ◽  
Thorsten A. Kranz ◽  
Juergen Fell ◽  
Christian E. Elger ◽  
...  

1998 ◽  
Vol 18 (11) ◽  
pp. 4305-4313 ◽  
Author(s):  
A-Min Huang ◽  
Hai Long Wang ◽  
Yu Ping Tang ◽  
Eminy H. Y. Lee

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Koilmani Emmanuvel Rajan ◽  
Jayakumar Preethi ◽  
Hemant K. Singh

Over the last 50 years, laboratories around the world analyzed the pharmacological effect ofBacopa monnieraextract in different dimensions, especially as a nerve tonic and memory enhancer. Studies in animal model evidenced thatBacopatreatment can attenuate dementia and enhances memory. Further, they demonstrate thatBacopaprimarily either acts via antioxidant mechanism (i.e., neuroprotection) or alters different neurotransmitters (serotonin (5-hydroxytryptamine, 5-HT), dopamine (DA), acetylcholine (ACh),γ-aminobutyric acid (GABA)) to execute the pharmacological effect. Among them, 5-HT has been shown to fine tune the neural plasticity, which is a substrate for memory formation. This review focuses on the studies which trace the effect ofBacopatreatment on serotonergic system and 5-HT mediated key molecular changes that are associated with memory formation.


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