scholarly journals Long term functional plasticity of sensory inputs mediated by olfactory learning

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Nixon M Abraham ◽  
Roberto Vincis ◽  
Samuel Lagier ◽  
Ivan Rodriguez ◽  
Alan Carleton

Sensory inputs are remarkably organized along all sensory pathways. While sensory representations are known to undergo plasticity at the higher levels of sensory pathways following peripheral lesions or sensory experience, less is known about the functional plasticity of peripheral inputs induced by learning. We addressed this question in the adult mouse olfactory system by combining odor discrimination studies with functional imaging of sensory input activity in awake mice. Here we show that associative learning, but not passive odor exposure, potentiates the strength of sensory inputs up to several weeks after the end of training. We conclude that experience-dependent plasticity can occur in the periphery of adult mouse olfactory system, which should improve odor detection and contribute towards accurate and fast odor discriminations.

Author(s):  
Daoming Lyu ◽  
Fangkai Yang ◽  
Bo Liu ◽  
Steven Gustafson

Deep reinforcement learning (DRL) has gained great success by learning directly from high-dimensional sensory inputs, yet is notorious for the lack of interpretability. Interpretability of the subtasks is critical in hierarchical decision-making as it increases the transparency of black-box-style DRL approach and helps the RL practitioners to understand the high-level behavior of the system better. In this paper, we introduce symbolic planning into DRL and propose a framework of Symbolic Deep Reinforcement Learning (SDRL) that can handle both high-dimensional sensory inputs and symbolic planning. The task-level interpretability is enabled by relating symbolic actions to options.This framework features a planner – controller – meta-controller architecture, which takes charge of subtask scheduling, data-driven subtask learning, and subtask evaluation, respectively. The three components cross-fertilize each other and eventually converge to an optimal symbolic plan along with the learned subtasks, bringing together the advantages of long-term planning capability with symbolic knowledge and end-to-end reinforcement learning directly from a high-dimensional sensory input. Experimental results validate the interpretability of subtasks, along with improved data efficiency compared with state-of-the-art approaches.


Author(s):  
Nixon M Abraham ◽  
Roberto Vincis ◽  
Samuel Lagier ◽  
Ivan Rodriguez ◽  
Alan Carleton

Author(s):  
Ray Guillery

My thesis studies had stimulated an interest in the mamillothalamic pathways but also some puzzlement because we knew nothing about the nature of the messages passing along these pathways. Several laboratories were studying the thalamic relay of sensory pathways with great success during my post-doctoral years. Each sensory relay could be understood in terms of the appropriate sensory input, but we had no way of knowing the meaning of the mamillothalamic messages. I introduce these nuclei as an example of the many thalamic nuclei about whose input functions we still know little or nothing. Early clinical studies of mamillary lesions had suggested a role in memory formation, whereas evidence from cortical lesions suggested a role in emotional experiences. Studies of the smallest of the three nuclei forming these pathways then showed it to be concerned with sensing head direction, relevant but not sufficient for defining an animal’s position in space. More recent studies based on studies of cortical activity or cortical damage have provided a plethora of suggestions: as so often, the answers reported depend on the questions asked. That simple conclusion is relevant for all transthalamic pathways. The evidence introduced in Chapter 1, that thalamocortical messages have dual meanings, suggests that we need to rethink our questions. It may prove useful to look at the motor outputs of relevant cortical areas to get clues about some appropriate questions.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yire Jeong ◽  
Hye-Yeon Cho ◽  
Mujun Kim ◽  
Jung-Pyo Oh ◽  
Min Soo Kang ◽  
...  

AbstractMemory is supported by a specific collection of neurons distributed in broad brain areas, an engram. Despite recent advances in identifying an engram, how the engram is created during memory formation remains elusive. To explore the relation between a specific pattern of input activity and memory allocation, here we target a sparse subset of neurons in the auditory cortex and thalamus. The synaptic inputs from these neurons to the lateral amygdala (LA) are not potentiated by fear conditioning. Using an optogenetic priming stimulus, we manipulate these synapses to be potentiated by the learning. In this condition, fear memory is preferentially encoded in the manipulated cell ensembles. This change, however, is abolished with optical long-term depression (LTD) delivered shortly after training. Conversely, delivering optical long-term potentiation (LTP) alone shortly after fear conditioning is sufficient to induce the preferential memory encoding. These results suggest a synaptic plasticity-dependent competition rule underlying memory formation.


2009 ◽  
Vol 297 (6) ◽  
pp. L1073-L1081 ◽  
Author(s):  
C. Mucignat-Caretta ◽  
M. Bondí ◽  
A. Rubini ◽  
F. Calabrese ◽  
A. Barbato

Asthma needs continuous treatment often for years. In humans, some drugs are administered via aerosol, therefore they come in contact with both respiratory and olfactory mucosa. We explored the possibility that antiasthma corticosteroid treatment could influence the olfactory function by passage through the nose. A group of mice was exposed twice daily for 42 days to fluticasone propionate aerosol and was compared with a control group. Olfactory behavior, respiratory mechanics, histology, and immunoreactivity in the olfactory system were assessed. Fluticasone-treated mice were slower in retrieving a piece of hidden food, but both groups were similarly fast when the food was visible. When a clearly detectable odor was present in the environment, all mice behaved in a similar way. Respiratory mechanics indices were similar in all mice except for the viscose resistance, which was reduced in fluticasone-treated mice. Olfactory mucosa of fluticasone-treated mice was thicker than that of controls. Slight but consistent differences in staining were present for Olfactory Marker Protein but not for other proteins. A mild impairment of olfactory function is present in mice chronically treated with fluticasone aerosol, apparently accompanied by slight modifications of the olfactory receptor cells, and suggests monitoring of olfactory function modifications in long-term steroid users.


Author(s):  
Silvia-Raluca Matei ◽  
Damian Mircea Totolan ◽  
Claudia Salceanu

Occupational therapy focuses on children's sensory processing and modulation. This chapter approaches specific interventions on children with ASD from several perspectives. OT is based on sensory integrative approach when working with children with ASD: helping parents understand their child's behavior, helping children organize responses to sensory input. The sensory integrative approach is a formulated activity plan that helps people who haven't been able to develop their own sensory recognition program. This plan allows a child to integrate all sorts of different sensory activities in their day so they can engage in and begin to work with a wide variety of sensory inputs. This provides a wide number of benefits. Their focus and attention span increases because they won't have meltdowns from trying to process too much information; sensory integrative approach helps to rebuild/reform the child's nervous system. This allows them to physically handle more sensory input. As a result, OT has been proven effective in working with children with ASD.


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