scholarly journals Thalamic olfaction: characterizing odor processing in the mediodorsal thalamus of the rat

2014 ◽  
Vol 111 (6) ◽  
pp. 1274-1285 ◽  
Author(s):  
Emmanuelle Courtiol ◽  
Donald A. Wilson
Keyword(s):  
Local Field ◽  
Local Field Potential ◽  
Piriform Cortex ◽  
Field Potential ◽  
Olfactory Perception ◽  
Olfactory Pathway ◽  
Odor Processing ◽  
State Dependent ◽  
Beta Frequency Band ◽  
Beta Frequency

Thalamus is a key crossroad structure involved in various functions relative to visual, auditory, gustatory, and somatosensory senses. Because of the specific organization of the olfactory pathway (i.e., no direct thalamic relay between sensory neurons and primary cortex), relatively little attention has been directed toward the thalamus in olfaction. However, an olfactory thalamus exists: the mediodorsal nucleus of the thalamus (MDT) receives input from various olfactory structures including the piriform cortex. How the MDT contributes to olfactory perception remains unanswered. The present study is a first step to gain insight into the function of the MDT in olfactory processing. Spontaneous and odor-evoked activities were recorded in both the MDT (single unit and local field potential) and the piriform cortex (local field potential) of urethane-anesthetized rats. We demonstrate that: 1) odorant presentation induces a conjoint, coherent emergence of beta-frequency-band oscillations in both the MDT and the piriform cortex; 2) 51% of MDT single units were odor-responsive with narrow-tuning characteristics across an odorant set, which included biological, monomolecular, and mixture stimuli. In fact, a majority of MDT units responded to only one odor within the set; 3) the MDT and the piriform cortex showed tightly related activities with, for example, nearly 20% of MDT firing in phase with piriform cortical beta-frequency oscillations; and 4) MDT-piriform cortex coherence was state-dependent with enhanced coupling during slow-wave activity. These data are discussed in the context of the hypothesized role of MDT in olfactory perception and attention.

scholarly journals Subthalamic nucleus activity dynamics and limb movement prediction in Parkinson’s disease

Brain ◽  
2020 ◽  
Vol 143 (2) ◽  
pp. 582-596 ◽  
Author(s):  
Saed Khawaldeh ◽  
Gerd Tinkhauser ◽  
Syed Ahmar Shah ◽  
Katrin Peterman ◽  
Ines Debove ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Basal Ganglia ◽  
Subthalamic Nucleus ◽  
Local Field ◽  
Local Field Potential ◽  
Field Potential ◽  
Beta Frequency Band ◽  
Potential Activity ◽  
Beta Frequency

Abstract Whilst exaggerated bursts of beta frequency band oscillatory synchronization in the subthalamic nucleus have been associated with motor impairment in Parkinson’s disease, a plausible mechanism linking the two phenomena has been lacking. Here we test the hypothesis that increased synchronization denoted by beta bursting might compromise information coding capacity in basal ganglia networks. To this end we recorded local field potential activity in the subthalamic nucleus of 18 patients with Parkinson’s disease as they executed cued upper and lower limb movements. We used the accuracy of local field potential-based classification of the limb to be moved on each trial as an index of the information held by the system with respect to intended action. Machine learning using the naïve Bayes conditional probability model was used for classification. Local field potential dynamics allowed accurate prediction of intended movements well ahead of their execution, with an area under the receiver operator characteristic curve of 0.80 ± 0.04 before imperative cues when the demanded action was known ahead of time. The presence of bursts of local field potential activity in the alpha, and even more so, in the beta frequency band significantly compromised the prediction of the limb to be moved. We conclude that low frequency bursts, particularly those in the beta band, restrict the capacity of the basal ganglia system to encode physiologically relevant information about intended actions. The current findings are also important as they suggest that local subthalamic activity may potentially be decoded to enable effector selection, in addition to force control in restorative brain-machine interface applications.

Odor- and state-dependent olfactory tubercle local field potential dynamics in awake rats

2014 ◽  
Vol 111 (10) ◽  
pp. 2109-2123 ◽  
Author(s):  
Kaitlin S. Carlson ◽  
Maggie R. Dillione ◽  
Daniel W. Wesson
Keyword(s):  
Local Field ◽  
Local Field Potential ◽  
Internal State ◽  
Respiratory Rhythm ◽  
Field Potential ◽  
Network Activity ◽  
Olfactory Tubercle ◽  
State Dependent ◽  
Awake Rat

The olfactory tubercle (OT), a trilaminar structure located in the basal forebrain of mammals, is thought to play an important role in olfaction. While evidence has accumulated regarding the contributions of the OT to odor information processing, studies exploring the role of the OT in olfaction in awake animals remain unavailable. In the present study, we begin to address this void through multiday recordings of local field potential (LFP) activity within the OT of awake, freely exploring Long-Evans rats. We observed spontaneous OT LFP activity consisting of theta- (2–12 Hz), beta- (15–35 Hz) and gamma- (40–80 Hz) band activity, characteristic of previous reports of LFPs in other principle olfactory structures. Beta- and gamma-band powers were enhanced upon odor presentation. Simultaneous recordings of OT and upstream olfactory bulb (OB) LFPs revealed odor-evoked LFP power at statistically similar levels in both structures. Strong spectral coherence was observed between the OT and OB during both spontaneous and odor-evoked states. Furthermore, the OB theta rhythm more strongly cohered with the respiratory rhythm, and respiratory-coupled theta cycles in the OT occurred following theta cycles in the OB. Finally, we found that the animal's internal state modulated LFP activity in the OT. Together, these data provide initial insights into the network activity of the OT in the awake rat, including spontaneous rhythmicity, odor-evoked modulation, connectivity with upstream sensory input, and state-dependent modulation.

scholarly journals Directional Coupling From the Olfactory Bulb to the Hippocampus During a Go/No-Go Odor Discrimination Task

2010 ◽  
Vol 103 (5) ◽  
pp. 2633-2641 ◽  
Author(s):  
Boris Gourévitch ◽  
Leslie M. Kay ◽  
Claire Martin
Keyword(s):  
Olfactory Bulb ◽  
Cognitive Processing ◽  
Information Transfer ◽  
Field Potential ◽  
Ventral Hippocampus ◽  
Beta Oscillations ◽  
Odor Processing ◽  
Odor Discrimination Task ◽  
Beta Frequency Band ◽  
Beta Frequency

The hippocampus and olfactory regions are anatomically close, and both play a major role in memory formation. However, the way they interact during odor processing is still unclear. In both areas, strong oscillations of the local field potential (LFP) can be recorded, and are modulated by behavior. In particular, in the olfactory system, the beta rhythm (15–35 Hz) is associated with cognitive processing of an olfactory stimulus. Using LFP recordings in the olfactory bulb and dorsal and ventral hippocampus during performance of an olfactory go/no-go task in rats, we previously showed that beta oscillations are also present in the hippocampus, coherent with those in the olfactory bulb, during odor sampling. In this study, we provide further insight into information transfer in the olfacto-hippocampal network by using directional coherence (DCOH estimate), a method based on the temporal relation between two or more signals in the frequency domain. In the theta band (6–12 Hz), coherence between the olfactory bulb (OB) and the hippocampus (HPC) is weak and can be both in the feedback and feedforward directions. However, at this frequency, modulation of the coupling between the dorsal and ventral hippocampus is seen during stimulus expectation versus odor processing. In the beta frequency band (15–35 Hz), analysis showed a strong unidirectional coupling from the OB to dorsal and ventral HPC, indicating that, during odor processing, beta oscillations in the hippocampus are driven by the olfactory bulb.

State-dependent entrainment of cerebellar nuclear neurons to the local field potential during voluntary movements

2021 ◽  
Author(s):  
Yuval Baumel ◽  
Dana Cohen
Keyword(s):  
Local Field ◽  
Local Field Potential ◽  
Phase Locking ◽  
Field Potential ◽  
Rhythmic Activity ◽  
Cerebellar Nuclei ◽  
Single Neurons ◽  
Band Frequency ◽  
Sensorimotor Network ◽  
State Dependent

Understanding the relationship between the local field potential (LFP) and single neurons is essential if we are to understand network dynamics and the entrainment of neuronal activity. Here, we investigated the interaction between the LFP and single neurons recorded in the rat cerebellar nuclei (CN), which are part of the sensorimotor network, in freely moving rats. During movement, the LFP displayed persistent oscillations in the theta band frequency whereas CN neurons displayed intermittent oscillations in the same frequency band contingent on the instantaneous LFP power; the neurons oscillated primarily when the concurrent LFP power was either high or low. Quantification of the relative instantaneous frequency and phase locking showed that CN neurons exhibited phase locked rhythmic activity at a frequency similar to that of the LFP or at a shifted frequency during high and low LFP power, respectively. We suggest that this nonlinear interaction between cerebellar neurons and the LFP power, which occurs solely during movement, contributes to the shaping of cerebellar output patterns.

Vagus Nerve Stimulation Induced Synchrony Modulation of Local Field Potential in the Rat Cerebral Cortex

2013 ◽  
Vol 133 (8) ◽  
pp. 1493-1500 ◽  
Author(s):  
Ryuji Kano ◽  
Kenichi Usami ◽  
Takahiro Noda ◽  
Tomoyo I. Shiramatsu ◽  
Ryohei Kanzaki ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Vagus Nerve ◽  
Local Field ◽  
Nerve Stimulation ◽  
Local Field Potential ◽  
Vagus Nerve Stimulation ◽  
Field Potential ◽  
Rat Cerebral Cortex
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