scholarly journals Spatial tuning and brain state account for dorsal hippocampal CA1 activity in a non-spatial learning task

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Kevin Q Shan ◽  
Evgueniy V Lubenov ◽  
Maria Papadopoulou ◽  
Athanassios G Siapas
Keyword(s):  
Spatial Learning ◽  
Pyramidal Neurons ◽  
Spatial Information ◽  
Eyeblink Conditioning ◽  
Brain Area ◽  
Learning Task ◽  
Spatial Task ◽  
Place Cells ◽  
Brain State ◽  
Output Stages

The hippocampus is a brain area crucial for episodic memory in humans. In contrast, studies in rodents have highlighted its role in spatial learning, supported by the discovery of place cells. Efforts to reconcile these views have found neurons in the rodent hippocampus that respond to non-spatial events but have not unequivocally dissociated the spatial and non-spatial influences on these cells. To disentangle these influences, we trained freely moving rats in trace eyeblink conditioning, a hippocampally dependent task in which the animal learns to blink in response to a tone. We show that dorsal CA1 pyramidal neurons are all place cells, and do not respond to the tone when the animal is moving. When the animal is inactive, the apparent tone-evoked responses reflect an arousal-mediated resumption of place-specific firing. These results suggest that one of the main output stages of the hippocampus transmits only spatial information, even in this non-spatial task.

scholarly journals Sex and boldness explain individual differences in spatial learning in a lizard

2014 ◽  
Vol 281 (1782) ◽  
pp. 20133275 ◽  
Author(s):  
Pau Carazo ◽  
Daniel W. A. Noble ◽  
Dani Chandrasoma ◽  
Martin J. Whiting
Keyword(s):  
Individual Differences ◽  
Cognitive Performance ◽  
Spatial Learning ◽  
Environmental Variability ◽  
Learning Task ◽  
Spatial Task ◽  
Individual Variability ◽  
Biologically Relevant ◽  
Trade Offs ◽  
Behavioural Types

Understanding individual differences in cognitive performance is a major challenge to animal behaviour and cognition studies. We used the Eastern water skink ( Eulamprus quoyii ) to examine associations between exploration, boldness and individual variability in spatial learning, a dimension of lizard cognition with important bearing on fitness. We show that males perform better than females in a biologically relevant spatial learning task. This is the first evidence for sex differences in learning in a reptile, and we argue that it is probably owing to sex-specific selective pressures that may be widespread in lizards. Across the sexes, we found a clear association between boldness after a simulated predatory attack and the probability of learning the spatial task. In contrast to previous studies, we found a nonlinear association between boldness and learning: both ‘bold’ and ‘shy’ behavioural types were more successful learners than intermediate males. Our results do not fit with recent predictions suggesting that individual differences in learning may be linked with behavioural types via high–low-risk/reward trade-offs. We suggest the possibility that differences in spatial cognitive performance may arise in lizards as a consequence of the distinct environmental variability and complexity experienced by individuals as a result of their sex and social tactics.

Neural Processing of Spatial Information: What We Know about Place Cells and What They Can Tell Us about Presence

2006 ◽  
Vol 15 (5) ◽  
pp. 485-499 ◽  
Author(s):  
Jorge R Brotons-Mas ◽  
Shane O'Mara ◽  
Maria V Sanchez-Vives
Keyword(s):  
Pyramidal Neurons ◽  
Brain Research ◽  
Spatial Information ◽  
Cognitive Maps ◽  
Place Cells ◽  
Neural Processing ◽  
Spatial Presence ◽  
Discrete Area ◽  
Internal Information ◽  
Brain Processing

Brain processing of spatial information is a very prolific area of research in neuroscience. Since the discovery of place cells (PCs)(O'Keefe & Dostrovsky, “The hippocampus as a spatial map,” Brain Research 34, 1971) researchers have tried to explain how these neurons integrate and process spatial and non-spatial information. Place cells are pyramidal neurons located in the hippocampus and parahippocampal region which fire with higher frequency when the animal is in a discrete area of space. Recently, PCs have been found in the human brain. The processing of spatial information and the creation of cognitive maps of the space is the result of the integration of multisensory external and internal information with the brain's own activity. In this article we review some of the most relevant properties of PCs and how this knowledge can be extended to the understanding of human processing of spatial information and to the generation of spatial presence.

scholarly journals Learning outdoors: male lizards show flexible spatial learning under semi-natural conditions

2012 ◽  
Vol 8 (6) ◽  
pp. 946-948 ◽  
Author(s):  
Daniel W. A. Noble ◽  
Pau Carazo ◽  
Martin J. Whiting
Keyword(s):  
Spatial Learning ◽  
Cognitive Abilities ◽  
Learning Task ◽  
Spatial Task ◽  
Lizard Species ◽  
Experimental Procedure ◽  
Biologically Relevant ◽  
Learning Outdoors ◽  
In The Wild ◽  
Spatial Learning Task

Spatial cognition is predicted to be a fundamental component of fitness in many lizard species, and yet some studies suggest that it is relatively slow and inflexible. However, such claims are based on work conducted using experimental designs or in artificial contexts that may underestimate their cognitive abilities. We used a biologically realistic experimental procedure (using simulated predatory attacks) to study spatial learning and its flexibility in the lizard Eulamprus quoyii in semi-natural outdoor enclosures under similar conditions to those experienced by lizards in the wild. To evaluate the flexibility of spatial learning, we conducted a reversal spatial-learning task in which positive and negative reinforcements of learnt spatial stimuli were switched. Nineteen (32%) male lizards learnt both tasks within 10 days (spatial task mean: 8.16 ± 0.69 (s.e.) and reversal spatial task mean: 10.74 ± 0.98 (s.e.) trials). We demonstrate that E. quoyii are capable of flexible spatial learning and suggest that future studies focus on a range of lizard species which differ in phylogeny and/or ecology, using biologically relevant cognitive tasks, in an effort to bridge the cognitive divide between ecto- and endotherms.

scholarly journals M-type potassium conductance controls the emergence of neural phase codes: a combined experimental and neuron modelling study

2014 ◽  
Vol 11 (99) ◽  
pp. 20140604 ◽  
Author(s):  
Jeehyun Kwag ◽  
Hyun Jae Jang ◽  
Mincheol Kim ◽  
Sujeong Lee
Keyword(s):  
Information Processing ◽  
Single Neuron ◽  
Pyramidal Neurons ◽  
Spatial Information ◽  
Potassium Conductance ◽  
Place Cells ◽  
Intrinsic Mechanism ◽  
Phase Precession

Rate and phase codes are believed to be important in neural information processing. Hippocampal place cells provide a good example where both coding schemes coexist during spatial information processing. Spike rate increases in the place field, whereas spike phase precesses relative to the ongoing theta oscillation. However, what intrinsic mechanism allows for a single neuron to generate spike output patterns that contain both neural codes is unknown. Using dynamic clamp, we simulate an in vivo -like subthreshold dynamics of place cells to in vitro CA1 pyramidal neurons to establish an in vitro model of spike phase precession. Using this in vitro model, we show that membrane potential oscillation (MPO) dynamics is important in the emergence of spike phase codes: blocking the slowly activating, non-inactivating K + current ( I M ), which is known to control subthreshold MPO, disrupts MPO and abolishes spike phase precession. We verify the importance of adaptive I M in the generation of phase codes using both an adaptive integrate-and-fire and a Hodgkin–Huxley (HH) neuron model. Especially, using the HH model, we further show that it is the perisomatically located I M with slow activation kinetics that is crucial for the generation of phase codes. These results suggest an important functional role of I M in single neuron computation, where I M serves as an intrinsic mechanism allowing for dual rate and phase coding in single neurons.

Personality tests predict responses to a spatial-learning task in mallards, Anas platyrhynchos

2015 ◽  
Vol 110 ◽  
pp. 145-154 ◽  
Author(s):  
Christophe A.H. Bousquet ◽  
Odile Petit ◽  
Mathilde Arrivé ◽  
Jean-Patrice Robin ◽  
Cédric Sueur
Keyword(s):  
Spatial Learning ◽  
Anas Platyrhynchos ◽  
Learning Task ◽  
Personality Tests ◽  
Spatial Learning Task

FosGFP expression does not capture a sensory learning-related engram in superficial layers of mouse barrel cortex

2021 ◽  
Vol 118 (52) ◽  
pp. e2112212118
Author(s):  
Jiseok Lee ◽  
Joanna Urban-Ciecko ◽  
Eunsol Park ◽  
Mo Zhu ◽  
Stephanie E. Myal ◽  
...  
Keyword(s):  
Pyramidal Neurons ◽  
Barrel Cortex ◽  
Sensory Information ◽  
Learning Task ◽  
Early Gene ◽  
Sensory Stimuli ◽  
Association Learning ◽  
Neural Ensembles ◽  
Dependent Learning

Immediate-early gene (IEG) expression has been used to identify small neural ensembles linked to a particular experience, based on the principle that a selective subset of activated neurons will encode specific memories or behavioral responses. The majority of these studies have focused on “engrams” in higher-order brain areas where more abstract or convergent sensory information is represented, such as the hippocampus, prefrontal cortex, or amygdala. In primary sensory cortex, IEG expression can label neurons that are responsive to specific sensory stimuli, but experience-dependent shaping of neural ensembles marked by IEG expression has not been demonstrated. Here, we use a fosGFP transgenic mouse to longitudinally monitor in vivo expression of the activity-dependent gene c-fos in superficial layers (L2/3) of primary somatosensory cortex (S1) during a whisker-dependent learning task. We find that sensory association training does not detectably alter fosGFP expression in L2/3 neurons. Although training broadly enhances thalamocortical synaptic strength in pyramidal neurons, we find that synapses onto fosGFP+ neurons are not selectively increased by training; rather, synaptic strengthening is concentrated in fosGFP− neurons. Taken together, these data indicate that expression of the IEG reporter fosGFP does not facilitate identification of a learning-specific engram in L2/3 in barrel cortex during whisker-dependent sensory association learning.

scholarly journals Lack of change in CA1 dendritic spine density or clustering in rats following training on a radial-arm maze task

2020 ◽  
Vol 5 ◽  
pp. 68
Author(s):  
Emma Craig ◽  
Christopher M. Dillingham ◽  
Michal M. Milczarek ◽  
Heather M. Phillips ◽  
Moira Davies ◽  
...  
Keyword(s):  
Dendritic Spines ◽  
Pyramidal Neurons ◽  
Memory Load ◽  
Spatial Location ◽  
Memory Formation ◽  
Spatial Task ◽  
Radial Arm Maze ◽  
Nearest Neighbour ◽  
Spine Density ◽  
Ca1 Region

Background: Neuronal plasticity is thought to underlie learning and memory formation. The density of dendritic spines in the CA1 region of the hippocampus has been repeatedly linked to mnemonic processes. Both the number and spatial location of the spines, in terms of proximity to nearest neighbour, have been implicated in memory formation. To examine how spatial training impacts synaptic structure in the hippocampus, Lister-Hooded rats were trained on a hippocampal-dependent spatial task in the radial-arm maze.  Methods: One group of rats were trained on a hippocampal-dependent spatial task in the radial arm maze. Two further control groups were included: a yoked group which received the same sensorimotor stimulation in the radial-maze but without a memory load, and home-cage controls. At the end of behavioural training, the brains underwent Golgi staining. Spines on CA1 pyramidal neuron dendrites were imaged and quantitatively assessed to provide measures of density and distance from nearest neighbour.  Results: There was no difference across behavioural groups either in terms of spine density or in the clustering of dendritic spines. Conclusions: Spatial learning is not always accompanied by changes in either the density or clustering of dendritic spines on the basal arbour of CA1 pyramidal neurons when assessed using Golgi imaging.

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