Identification of Basolateral Amygdala Projection Cells and Interneurons Using Extracellular Recordings

2006 ◽  
Vol 96 (6) ◽  
pp. 3257-3265 ◽  
Author(s):  
Ekaterina Likhtik ◽  
Joe Guillaume Pelletier ◽  
Andrei T. Popescu ◽  
Denis Paré
Keyword(s):  
Firing Rate ◽  
Basolateral Amygdala ◽  
Cell Group ◽  
Small Subset ◽  
Cortical Projection ◽  
Antidromic Activation ◽  
Extracellular Recordings ◽  
Firing Rates ◽  
Cell Groups ◽  
Exact Position

This study tested whether firing rate and spike shape could be used to distinguish projection cells from interneurons in extracellular recordings of basolateral amygdala (BLA) neurons. To this end, we recorded BLA neurons in isoflurane-anesthetized animals with tungsten microelectrodes. Projection cells were identified by antidromic activation from cortical projection sites of the BLA. Although most projection cells fired spontaneously at low rates (<1 Hz), an important subset fired at higher rates (up to 6.8 Hz). In fact, the distribution of firing rates in projection cells and unidentified BLA neurons overlapped extensively, even though the latter cell group presumably contains a higher proportion of interneurons. The only difference between the two distributions was a small subset (5.1%) of unidentified neurons with unusually high firing rates (9–16 Hz). Similarly, distributions of spike durations in both cell groups were indistinguishable, although most of the fast-firing neurons had spike durations at the low end of the distribution. However, we observed that spike durations depended on the exact position of the electrode with respect to the recorded cell, varying by as much as 0.7 ms. Thus neither firing rate nor spike waveform allowed for unequivocal separation of projection cells from interneurons. Nevertheless, we propose the use of two firing rate cutoffs to obtain relatively pure samples of projection cells and interneurons: ≤1 Hz for projection cells and ≥7 Hz for fast-spiking interneurons. Supplemented with spike-duration cutoffs of ≥0.7 ms for projection cells and ≤0.5 ms for interneurons, this approach should keep instances of misclassifications to a minimum.

scholarly journals A deep convolutional visual encoding model of neuronal responses in the LGN

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Eslam Mounier ◽  
Bassem Abdullah ◽  
Hani Mahdi ◽  
Seif Eldawlatly
Keyword(s):  
Firing Rate ◽  
Visual Information ◽  
Visual Stimulation ◽  
Neuronal Population ◽  
Neuronal Firing ◽  
Electrode Arrays ◽  
Deep Convolutional Neural Networks ◽  
Firing Rates ◽  
Spatiotemporal Representation

AbstractThe Lateral Geniculate Nucleus (LGN) represents one of the major processing sites along the visual pathway. Despite its crucial role in processing visual information and its utility as one target for recently developed visual prostheses, it is much less studied compared to the retina and the visual cortex. In this paper, we introduce a deep learning encoder to predict LGN neuronal firing in response to different visual stimulation patterns. The encoder comprises a deep Convolutional Neural Network (CNN) that incorporates visual stimulus spatiotemporal representation in addition to LGN neuronal firing history to predict the response of LGN neurons. Extracellular activity was recorded in vivo using multi-electrode arrays from single units in the LGN in 12 anesthetized rats with a total neuronal population of 150 units. Neural activity was recorded in response to single-pixel, checkerboard and geometrical shapes visual stimulation patterns. Extracted firing rates and the corresponding stimulation patterns were used to train the model. The performance of the model was assessed using different testing data sets and different firing rate windows. An overall mean correlation coefficient between the actual and the predicted firing rates of 0.57 and 0.7 was achieved for the 10 ms and the 50 ms firing rate windows, respectively. Results demonstrate that the model is robust to variability in the spatiotemporal properties of the recorded neurons outperforming other examined models including the state-of-the-art Generalized Linear Model (GLM). The results indicate the potential of deep convolutional neural networks as viable models of LGN firing.

scholarly journals Cell-specific expression and individual function of prohormone convertase PC1/3 in Tribolium larval growth highlights major evolutionary changes between beetle and fly neuroendocrine systems

EvoDevo ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sonja Fritzsche ◽  
Vera S. Hunnekuhl
Keyword(s):  
Larval Growth ◽  
Neuroendocrine System ◽  
Small Subset ◽  
Specific Cell ◽  
Specific Expression ◽  
Individual Function ◽  
Evolutionary Changes ◽  
Cell Groups ◽  
Cell Type Specific Expression ◽  
And Function

Abstract Background The insect neuroendocrine system acts in the regulation of physiology, development and growth. Molecular evolution of this system hence has the potential to allow for major biological differences between insect groups. Two prohormone convertases, PC1/3 and PC2, are found in animals and both function in the processing of neuropeptide precursors in the vertebrate neurosecretory pathway. Whereas PC2-function is conserved between the fly Drosophila and vertebrates, ancestral PC1/3 was lost in the fly lineage and has not been functionally studied in any protostome. Results In order to understand its original functions and the changes accompanying the gene loss in the fly, we investigated PC1/3 and PC2 expression and function in the beetle Tribolium castaneum. We found that PC2 is broadly expressed in the nervous system, whereas surprisingly, PC1/3 expression is restricted to specific cell groups in the posterior brain and suboesophageal ganglion. Both proteases have parallel but non-redundant functions in adult beetles’ viability and fertility. Female infertility following RNAi is caused by a failure to deposit sufficient yolk to the developing oocytes. Larval RNAi against PC2 produced moulting defects where the larvae were not able to shed their old cuticle. This ecdysis phenotype was also observed in a small subset of PC1/3 knockdown larvae and was strongest in a double knockdown. Unexpectedly, most PC1/3-RNAi larvae showed strongly reduced growth, but went through larval moults despite minimal to zero weight gain. Conclusions The cell type-specific expression of PC1/3 and its essential requirement for larval growth highlight the important role of this gene within the insect neuroendocrine system. Genomic conservation in most insect groups suggests that it has a comparable individual function in other insects as well, which has been replaced by alternative mechanisms in flies.

Encoding timing and intensity in the ventral cochlear nucleus of the cat

1986 ◽  
Vol 56 (2) ◽  
pp. 261-286 ◽  
Author(s):  
W. S. Rhode ◽  
P. H. Smith
Keyword(s):  
Firing Rate ◽  
Cochlear Nucleus ◽  
Auditory Nerve ◽  
Cell Types ◽  
Nerve Fibers ◽  
Frequency Selectivity ◽  
Firing Rates ◽  
Ventral Cochlear Nucleus ◽  
Auditory Nerve Fibers ◽  
Different Cell Types

Physiological response properties of neurons in the ventral cochlear nucleus have a variety of features that are substantially different from the stereotypical auditory nerve responses that serve as the principal source of activation for these neurons. These emergent features are the result of the varying distribution of auditory nerve inputs on the soma and dendrites of the various cell types within the nucleus; the intrinsic membrane characteristics of the various cell types causing different responses to the same input in different cell types; and secondary excitatory and inhibitory inputs to different cell types. Well-isolated units were recorded with high-impedance glass microelectrodes, both intracellularly and extracellularly. Units were characterized by their temporal response to short tones, rate vs. intensity relation, and response areas. The principal response patterns were onset, chopper, and primary-like. Onset units are characterized by a well-timed first spike in response to tones at the characteristic frequency. For frequencies less than 1 kHz, onset units can entrain to the stimulus frequency with greater precision than their auditory nerve inputs. This implies that onset units receive converging inputs from a number of auditory nerve fibers. Onset units are divided into three subcategories, OC, OL, and OI. OC units have extraordinarily wide dynamic ranges and low-frequency selectivity. Some are capable of sustaining firing rates of 800 spikes/s at high intensities. They have the smallest standard deviation and coefficient of variation of the first spike latency of any cells in the cochlear nuclei. OC units are candidates for encoding intensity. OI and OL units differ from OC units in that they have dynamic ranges and frequency selectivity ranges much like those of auditory nerve fibers. They differ from one another in their steady-state firing rates; OI units fire mainly at the onset of a tone. OI units also differ from OL units in that they prefer frequency sweeps in the low to high direction. Primary-like-with-notch (PLN) units also respond to tones with a well-timed first spike. They differ from onset cells in that the onset peak is not always as precise as the spontaneous rate is higher. A comparison of spontaneous firing rate and saturation firing rate of PLN units with auditory nerve fibers suggest that PLN units receive one to four auditory nerve fiber inputs. Chopper units fire in a sustained regular manner when they are excited by sound.(ABSTRACT TRUNCATED AT 400 WORDS)

Functional Properties of Single Motor Units in the Inferior Head of Human Lateral Pterygoid Muscle: Task Firing Rates

2002 ◽  
Vol 88 (2) ◽  
pp. 751-760 ◽  
Author(s):  
I. Phanachet ◽  
T. Whittle ◽  
K. Wanigaratne ◽  
G. M. Murray
Keyword(s):  
Firing Rate ◽  
Correlation Coefficients ◽  
Motor Units ◽  
Lateral Pterygoid Muscle ◽  
Jaw Movements ◽  
Firing Rates ◽  
Single Motor ◽  
Single Motor Units ◽  
Fine Control ◽  
Contralateral Movement

The precise function of the inferior head of the human lateral pterygoid muscle (IHLP) is unclear. The aim of this study was to clarify the normal function of the IHLP. The hypothesis was that an important function of the IHLP is the generation and fine control of horizontal (i.e., anteroposterior and mediolateral) jaw movements. The activities of 50 single motor units (SMUs) were recorded from IHLP (14 subjects) during two- or three-step contralateral movement ( n = 36) and/or protrusion ( n = 33). Most recording sites were identified by computer tomography. There was a statistically significant overall increase in firing rate as the magnitude of jaw displacement increased between the holding phases (range of increments: 0.3–1.6 mm). The firing rates during the dynamic phases for each unit were significantly greater than those during the previous holding phases but less than those during the subsequent holding phases. For the contralateral step task at the intermediate rate, the cross-correlation coefficients between jaw displacement in the mediolateral axis and the mean firing rate of each unit ranged from r = 0.29 to 0.77; mean ± SD; r = 0.49 ± 0.13 (protrusive step task: r = 0.12–0.74, r = 0.44 ± 0.14 for correlation with anterior–posterior axis). The correlation coefficients at the fast rate during the contralateral step task and the protrusive step task were significantly higher than those at the slow rate. The firing rate change of the SMUs per unit displacement between holding phases was significantly greater for the lower-threshold than for the higher-threshold units during contralateral movement and protrusion. After dividing IHLP into four regions, the SMUs recorded in the superior part exhibited significantly greater mean firing rate changes per unit displacement during protrusion than for the SMUs recorded in the inferior part. Significantly fewer units were related to the protrusive task in the superior–medial part. These data support previously proposed notions of functional heterogeneity within IHLP. The present findings provide further evidence for an involvement of the IHLP in the generation and fine control of horizontal jaw movements.

scholarly journals Multimodal Medullary Neurons and Correlational Linkages of the Respiratory Network

1999 ◽  
Vol 82 (1) ◽  
pp. 188-201 ◽  
Author(s):  
Zhongzeng Li ◽  
Kendall F. Morris ◽  
David M. Baekey ◽  
Roger Shannon ◽  
Bruce G. Lindsey
Keyword(s):  
Firing Rate ◽  
Nucleus Tractus Solitarius ◽  
Motor Pattern ◽  
Sensory Modality ◽  
Spike Trains ◽  
Negative Feedback Regulation ◽  
Firing Rates ◽  
Respiratory Network ◽  
Cross Correlation Analysis ◽  
Stimulation Of

This study addresses the hypothesis that multiple sensory systems, each capable of reflexly altering breathing, jointly influence neurons of the brain stem respiratory network. Carotid chemoreceptors, baroreceptors, and foot pad nociceptors were stimulated sequentially in 33 Dial-urethan–anesthetized or decerebrate vagotomized adult cats. Neuronal impulses were monitored with microelectrode arrays in the rostral and caudal ventral respiratory group (VRG), nucleus tractus solitarius (NTS), and n. raphe obscurus. Efferent phrenic nerve activity was recorded. Spike trains of 889 neurons were analyzed with cycle-triggered histograms and tested for respiratory-modulated firing rates. Responses to stimulus protocols were assessed with peristimulus time and cumulative sum histograms. Cross-correlation analysis was used to test for nonrandom temporal relationships between spike trains. Spike-triggered averages of efferent phrenic activity and antidromic stimulation methods provided evidence for functional associations of bulbar neurons with phrenic motoneurons. Spike train cross-correlograms were calculated for 6,471 pairs of neurons. Significant correlogram features were detected for 425 pairs, including 189 primary central peaks or troughs, 156 offset peaks or troughs, and 80 pairs with multiple peaks and troughs. The results provide evidence that correlational medullary assemblies include neurons with overlapping memberships in groups responsive to different sets of sensory modalities. The data suggest and support several hypotheses concerning cooperative relationships that modulate the respiratory motor pattern. 1) Neurons responsive to a single tested modality promote or limit changes in firing rate of multimodal target neurons. 2) Multimodal neurons contribute to changes in firing rate of neurons responsive to a single tested modality. 3) Multimodal neurons may promote responses during stimulation of one modality and “limit” changes in firing rates during stimulation of another sensory modality. 4) Caudal VRG inspiratory neurons have inhibitory connections that provide negative feedback regulation of inspiratory drive and phase duration.

Quantitative Analysis of Abducens Neuron Discharge Dynamics During Saccadic and Slow Eye Movements

1999 ◽  
Vol 82 (5) ◽  
pp. 2612-2632 ◽  
Author(s):  
Pierre A. Sylvestre ◽  
Kathleen E. Cullen
Keyword(s):  
Eye Movements ◽  
Firing Rate ◽  
Eye Movement ◽  
Neuronal Activity ◽  
Smooth Pursuit ◽  
Slow Phase ◽  
Vestibular Nystagmus ◽  
Firing Rates ◽  
Rapid Eye Movements ◽  
Eye Velocity

The mechanics of the eyeball and its surrounding tissues, which together form the oculomotor plant, have been shown to be the same for smooth pursuit and saccadic eye movements. Hence it was postulated that similar signals would be carried by motoneurons during slow and rapid eye movements. In the present study, we directly addressed this proposal by determining which eye movement–based models best describe the discharge dynamics of primate abducens neurons during a variety of eye movement behaviors. We first characterized abducens neuron spike trains, as has been classically done, during fixation and sinusoidal smooth pursuit. We then systematically analyzed the discharge dynamics of abducens neurons during and following saccades, during step-ramp pursuit and during high velocity slow-phase vestibular nystagmus. We found that the commonly utilized first-order description of abducens neuron firing rates (FR = b + kE + rE˙, where FR is firing rate, E and E˙ are eye position and velocity, respectively, and b, k, and r are constants) provided an adequate model of neuronal activity during saccades, smooth pursuit, and slow phase vestibular nystagmus. However, the use of a second-order model, which included an exponentially decaying term or “slide” (FR = b + kE + rE˙ + uË − c[Formula: see text]), notably improved our ability to describe neuronal activity when the eye was moving and also enabled us to model abducens neuron discharges during the postsaccadic interval. We also found that, for a given model, a single set of parameters could not be used to describe neuronal firing rates during both slow and rapid eye movements. Specifically, the eye velocity and position coefficients ( r and k in the above models, respectively) consistently decreased as a function of the mean (and peak) eye velocity that was generated. In contrast, the bias ( b, firing rate when looking straight ahead) invariably increased with eye velocity. Although these trends are likely to reflect, in part, nonlinearities that are intrinsic to the extraocular muscles, we propose that these results can also be explained by considering the time-varying resistance to movement that is generated by the antagonist muscle. We conclude that to create realistic and meaningful models of the neural control of horizontal eye movements, it is essential to consider the activation of the antagonist, as well as agonist motoneuron pools.

scholarly journals Position-theta-phase model of hippocampal place cell activity applied to quantification of running speed modulation of firing rate

2019 ◽  
Author(s):  
Kathryn McClain ◽  
David Tingley ◽  
David Heeger ◽  
György Buzsáki
Keyword(s):  
Firing Rate ◽  
Spatial Information ◽  
Cell Activity ◽  
Gain Control ◽  
Place Cell ◽  
Small Subset ◽  
Running Speed ◽  
Speed Modulation ◽  
Place Fields ◽  
Theta Phase

AbstractSpiking activity of place cells in the hippocampus encodes the animal’s position as it moves through an environment. Within a cell’s place field, both the firing rate and the phase of spiking in the local theta oscillation contain spatial information. We propose a position-theta-phase (PTP) model that captures the simultaneous expression of the firing-rate code and theta-phase code in place cell spiking. This model parametrically characterizes place fields to compare across cells, time and condition, generates realistic place cell simulation data, and conceptualizes a framework for principled hypothesis testing to identify additional features of place cell activity. We use the PTP model to assess the effect of running speed in place cell data recorded from rats running on linear tracks. For the majority of place fields we do not find evidence for speed modulation of the firing rate. For a small subset of place fields, we find firing rates significantly increase or decrease with speed. We use the PTP model to compare candidate mechanisms of speed modulation in significantly modulated fields, and determine that speed acts as a gain control on the magnitude of firing rate. Our model provides a tool that connects rigorous analysis with a computational framework for understanding place cell activity.SignificanceThe hippocampus is heavily studied in the context of spatial navigation, and the format of spatial information in hippocampus is multifaceted and complex. Furthermore, the hippocampus is also thought to contain information about other important aspects of behavior such as running speed, though there is not agreement on the nature and magnitude of their effect. To understand how all of these variables are simultaneously represented and used to guide behavior, a theoretical framework is needed that can be directly applied to the data we record. We present a model that captures well-established spatial-encoding features of hippocampal activity and provides the opportunity to identify and incorporate novel features for our collective understanding.

scholarly journals Specifically Binding of D-Amino Neuraminic Acid to Ganglioside Studied in Prostate Cancer Cells

2021 ◽  
Author(s):  
Kenan Demir ◽  
Huseyin Aktug ◽  
Gurkan Yigitturk ◽  
Eda Acikgoz ◽  
Gunnur Guler ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Enzyme Inhibitor ◽  
Cancer Cell Line ◽  
Prostate Cancer Cell Line ◽  
Cell Group ◽  
Synthesis Inhibitor ◽  
Cell Groups ◽  
Negative Effect ◽  
Synthase Inhibitor

Abstract Aims: The aim of this study was to investigate the cellular binding site of human KDN (2-keto-3-deoxy-D-glycero-D-galacto-nononic acid). The KDN molecule is a member of the sialic acid family, and its expression increases in cancer cells. Although KDN has been shown to bind to GM3 (Monosialodihexosyl Ganglioside) in trout sperm.Methods and Results: Prostate cancer cell line (DU145) was used in this study. Each experimental group was divided into 3 groups: control, GCS (Glucosylceramide synthase) enzyme inhibitor Genz-123346 treated, and GM3 synthesis inhibitor Triptolide treated. Each group was stained using the immunocytochemical method for GM3, GD3 (Disialosyllactosylceramide) and KDN. The FTIR (Fourier Transform Infrared Spectroscopy) analysis was performed to elucidate the cellular changes upon treatment. The non-treated number 1 cell group stained positive with all of GM3, GD3 and KDN, the GCS enzyme blocked with Genz-123346 number 2 cell groups stained positive with only KDN. Furthermore, GD3 Synthase inhibitor Triptolide treated number 3 cell group stained positive with GM3 and KDN. Measurements with FTIR showed apoptotic features with Triptolide while Genz-123346 had no negative effect on the cell viability. The decrease in sugar constructions was revealed and the results that we obtained with staining were reinforced.Conclusions: Determining the location of bounded KDN is important in selecting new targets for cancer treatment researches. It has been shown that KDN is not inhibited by both GM3 inhibition and GD3 inhibition, and thus, KDN might also bind to different places, be specific, and not only attached to any of gangliosides of the GM or GD series.

Intensity responses of the single auditory receptor of notodontid moths: a test of the peripheral interaction hypothesis in moth ears

1998 ◽  
Vol 201 (24) ◽  
pp. 3419-3424 ◽  
Author(s):  
J. H. Fullard ◽  
E. Forrest ◽  
A. Surlykke
Keyword(s):  
Firing Rate ◽  
B Cell ◽  
Receptor Cell ◽  
Laser Vibrometry ◽  
Firing Rates ◽  
Interaction Hypothesis ◽  
Peripheral Interaction ◽  
Auditory Receptor ◽  
Receptor Adaptation ◽  
High Stimulus

It has been proposed that the most sensitive auditory receptor cell (A1)in the two-celled ears of certain noctuoid moths is inhibited by its partner, the A2 cell, at high stimulus intensities. We used the single-celled ears of notodontid moths, also noctuoids, to test this hypothesis. The A1 cells of all but one of the moths tested exhibited non-monotonic firing rates, with reduced firing rates at high stimulus intensities and showing no relationship to the firing rate of the only other receptor, the non-auditory B cell. These results challenge the peripheral interaction hypothesis for A1 firing patterns in two-celled moth ears. An examination of notodontid A1 adaptation rates and laser vibrometry results suggests that receptor adaptation and tympanal motion non-linearity are more likely explanations for the non-monotonic receptor firing observed in both single- and multi-celled moth ears.

Roles of Endogenous IL-10 and IL-10-Competent and CD5+ B Cells in Autoimmune Thyroiditis in NOD.H-2h4 Mice

Endocrinology ◽  
2020 ◽  
Vol 161 (4) ◽  
Author(s):  
Jing Qin ◽  
Na Zhao ◽  
Shuo Wang ◽  
Shanshan Liu ◽  
Yongping Liu ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Autoimmune Thyroiditis ◽  
Flow Cytometric Analysis ◽  
Cell Group ◽  
Autoantibody Production ◽  
Flow Cytometric ◽  
Cell Groups ◽  
Regulatory Capacity ◽  
Anti Inflammatory Cytokine

Abstract Interleukin (IL)-10 is a highly important anti-inflammatory cytokine in the immune system. CD1dhi and CD5+ B cells are both traditionally defined IL-10-secreting B cells. In recent years, a B cell group with combined markers of CD1dhi and CD5+ has been widely studied as it has been reported to suppress autoimmunity in mouse models of autoimmune diseases through IL-10 mechanisms. From the perspective of origination, CD1dhi and CD5+ B cells are developed from different B cell lineages. Whether the regulatory capacity of these 2 B cell groups is consistent with their ability to secrete IL-10 has not been determined. In this study, we generated IL-10 knockout NOD.H-2h4 mice to investigate the function of endogenous IL-10 in autoimmune thyroiditis and conducted adoptive transfer experiments to explore the respective roles of CD5+ and CD1dhi B cells. In our results, the IL-10–/– NOD.H-2h4 mice developed thyroiditis, similar to wild-type NOD.H-2h4 mice. The CD5+ B cells were more capable of secreting IL-10 than CD1dhi B cells in flow cytometric analysis, but the CD1dhi B cells showed more suppressive effects on thyroiditis development and autoantibody production, as well as Th17 cell response. In conclusion, endogenous IL-10 does not play an important role in autoimmune thyroiditis. CD1dhi B cells may play regulatory roles through mechanisms other than secreting IL-10.

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