scholarly journals Models of vestibular semicircular canal afferent neuron firing activity

2019 ◽  
Vol 122 (6) ◽  
pp. 2548-2567 ◽  
Author(s):  
Michael G. Paulin ◽  
Larry F. Hoffman

Semicircular canal afferent neurons transmit information about head rotation to the brain. Mathematical models of how they do this have coevolved with concepts of how brains perceive the world. A 19th-century “camera” metaphor, in which sensory neurons project an image of the world captured by sense organs into the brain, gave way to a 20th-century view of sensory nerves as communication channels providing inputs to dynamical control systems. Now, in the 21st century, brains are being modeled as Bayesian observers who infer what is happening in the world given noisy, incomplete, and distorted sense data. The semicircular canals of the vestibular apparatus provide an experimentally accessible, low-dimensional system for developing and testing dynamical Bayesian generative models of sense data. In this review, we summarize advances in mathematical modeling of information transmission by semicircular canal afferent sensory neurons since the first such model was proposed nearly a century ago. Models of information transmission by vestibular afferent neurons may provide a foundation for developing realistic models of how brains perceive the world by inferring the causes of sense data.

2013 ◽  
Vol 25 (6) ◽  
pp. 1371-1407 ◽  
Author(s):  
Stefan Habenschuss ◽  
Helmut Puhr ◽  
Wolfgang Maass

The brain faces the problem of inferring reliable hidden causes from large populations of noisy neurons, for example, the direction of a moving object from spikes in area MT. It is known that a theoretically optimal likelihood decoding could be carried out by simple linear readout neurons if weights of synaptic connections were set to certain values that depend on the tuning functions of sensory neurons. We show here that such theoretically optimal readout weights emerge autonomously through STDP in conjunction with lateral inhibition between readout neurons. In particular, we identify a class of optimal STDP learning rules with homeostatic plasticity, for which the autonomous emergence of optimal readouts can be explained on the basis of a rigorous learning theory. This theory shows that the network motif we consider approximates expectation-maximization for creating internal generative models for hidden causes of high-dimensional spike inputs. Notably, we find that this optimal functionality can be well approximated by a variety of STDP rules beyond those predicted by theory. Furthermore, we show that this learning process is very stable and automatically adjusts weights to changes in the number of readout neurons, the tuning functions of sensory neurons, and the statistics of external stimuli.


2018 ◽  
Author(s):  
Beren Millidge ◽  
Richard Shillcock

We propose a novel predictive processing account of bottom-up visual saliency in which salience is simply the low-level prediction error between the sense-data and the predictions produced by the generative models in the brain. We test this with modelling in which we use cross-predicting deep autoencoders to create salience maps in an entirely unsupervised way. The resulting maps closely mimic experimentally derived human saliency maps and also spontaneously learn a centre bias, a robust viewing behaviour seen in human participants.


Author(s):  
Qasim Aziz ◽  
James K. Ruffle

“It’s a gut feeling.” Indeed, how and why do we get “gut feelings?” After the brain, the gut is the second most innervated bodily organ, diffusely interconnected with gastrointestinal afferent neurons. Whilst sensory neurons from the gut ascend by means of the spinal cord and vagal nerve to subcortical and higher cortical areas of the brain, caudally descending motor efferents from brain to gut seek to modulate gastrointestinal function. Such is the construct of the “brain–gut axis,” a bi-directional body nexus permitting constant information transfer between both brain and gut so as to provide us with visceral interoception. This chapter reviews the neurobiology of gut feelings and discuss their role in both physical and mental health and disease.


2017 ◽  
Vol 28 (1) ◽  
pp. 45-57 ◽  
Author(s):  
Ivan Ezquerra-Romano ◽  
Angel Ezquerra

AbstractTemperature maintenance and detection are essential for the survival and perpetuation of any species. This review is focused on thermosensation; thus a detailed and traced explanation of the anatomical and physiological characteristics of each component of this sensation is given. First, the proteins that react to temperature changes are identified; next, the nature of the neurons involved in thermosensation is described; and then, the pathways from the skin through the spinal cord to the brain are outlined. Finally, the areas of the brain and their interconnections where thermoperception arises are explained. Transduction of the external and internal temperature information is essentially mediated by the transient receptor potential ion channels (TRPs). These proteins are embedded in the neurons’ membrane and they hyper- or de-polarize neurons in function of the intrinsic voltage and the temperature changes. There are distinct TRP sensors for different temperature ranges. Interestingly, the primary afferent neurons have either cold or hot receptors, so they are dedicated separately to cold or hot sensation. The information is transmitted by different pathways from the skin to the brain, where it either remains separated or is integrated to generate a response. It seems that both the determination of how thermoperception is produced and how we interact with the world are dependent on the particular arrangement and nature of the components, the way of transduction of information and the communication between these elements.


Author(s):  
S.S. Spicer ◽  
B.A. Schulte

Generation of monoclonal antibodies (MAbs) against tissue antigens has yielded several (VC1.1, HNK- 1, L2, 4F4 and anti-leu 7) which recognize the unique sugar epitope, glucuronyl 3-sulfate (Glc A3- SO4). In the central nervous system, these MAbs have demonstrated Glc A3-SO4 at the surface of neurons in the cerebral cortex, the cerebellum, the retina and other widespread regions of the brain.Here we describe the distribution of Glc A3-SO4 in the peripheral nervous system as determined by immunostaining with a MAb (VC 1.1) developed against antigen in the cat visual cortex. Outside the central nervous system, immunoreactivity was observed only in peripheral terminals of selected sensory nerves conducting transduction signals for touch, hearing, balance and taste. On the glassy membrane of the sinus hair in murine nasal skin, just deep to the ringwurt, VC 1.1 delineated an intensely stained, plaque-like area (Fig. 1). This previously unrecognized structure of the nasal vibrissae presumably serves as a tactile end organ and to our knowledge is not demonstrable by means other than its selective immunopositivity with VC1.1 and its appearance as a densely fibrillar area in H&E stained sections.


GYNECOLOGY ◽  
2020 ◽  
Vol 22 (5) ◽  
pp. 84-86
Author(s):  
Sergei P. Sinchikhin ◽  
Sarkis G. Magakyan ◽  
Oganes G. Magakyan

Relevance.A neoplasm originated from the myelonic sheath of the nerve trunk is called neurinoma or neurilemmoma, neurinoma, schwannoglioma, schwannoma. This tumor can cause compression and dysfunction of adjacent tissues and organs. The most common are the auditory nerve neurinomas (1 case per 100 000 population per year), the brain and spinal cord neurinomas are rare. In the world literature, there is no information on the occurrences of this tumor in the pelvic region. Description.Presented below is a clinical observation of a 30-year-old patient who was scheduled for myomectomy. During laparoscopy, an unusual tumor of the small pelvis was found and radically removed. A morphological study allowed to identify the remote neoplasm as a neuroma. Conclusion.The presented practical case shows that any tumor can hide under a clinical mask of another disease. The qualification of the doctor performing laparoscopic myomectomy should be sufficient to carry out, if necessary, another surgical volume.


2018 ◽  
Author(s):  
Xiaoyang Yu

Nomological determinism does not mean everything is predictable. It just means everything follows the law of nature. And the most important thing Is that the brain and consciousness follow the law of nature. In other words, there is no free will. Without life, brain and consciousness, the world follows law of nature, that is clear. The life and brain are also part of nature, and they follow the law of nature. This is due to scientific findings. There are not enough scientific findings for consciousness yet. But I think that the consciousness is a nature phenomenon, and it also follows the law of nature.


Author(s):  
Bhumika Chauhan ◽  
Sisir Nandi

: The world is connected by the internet. It is very useful because we use Google to find out any new topic, to search new places, to quest updated research, and to get knowledge for learnng. The person around the world can communicate with each other through the Google video conference talk. Internet is frequently used in smartphones, laptops, desktop, and tablet. Excessive affinity towards internet-based online data collection, downloading pictures, videos, cyber relationships, and social media may produce addiction disorders followed by different symptoms such as behaviors change, mind disturbance, depression, anxiety, loss of appetite hyperactivity, sleeping disorder, headache, visual fatigueness, trafficking of memory, attention-deficit, loss of efficiency in work and social detachment which may be caused by an imbalance of neurotransmitters. This is very difficult to control because of abnormal signal transduction in the brain. The present study is an attempt to discuss internet addiction disorder (IAD), internet gaming disorder (IGD), and give awareness to society to get rid of this addiction.


2015 ◽  
Vol 113 (2) ◽  
pp. 657-668 ◽  
Author(s):  
Rafael Levi ◽  
Otar Akanyeti ◽  
Aleksander Ballo ◽  
James C. Liao

The ability of fishes to detect water flow with the neuromasts of their lateral line system depends on the physiology of afferent neurons as well as the hydrodynamic environment. Using larval zebrafish ( Danio rerio), we measured the basic response properties of primary afferent neurons to mechanical deflections of individual superficial neuromasts. We used two types of stimulation protocols. First, we used sine wave stimulation to characterize the response properties of the afferent neurons. The average frequency-response curve was flat across stimulation frequencies between 0 and 100 Hz, matching the filtering properties of a displacement detector. Spike rate increased asymptotically with frequency, and phase locking was maximal between 10 and 60 Hz. Second, we used pulse train stimulation to analyze the maximum spike rate capabilities. We found that afferent neurons could generate up to 80 spikes/s and could follow a pulse train stimulation rate of up to 40 pulses/s in a reliable and precise manner. Both sine wave and pulse stimulation protocols indicate that an afferent neuron can maintain their evoked activity for longer durations at low stimulation frequencies than at high frequencies. We found one type of afferent neuron based on spontaneous activity patterns and discovered a correlation between the level of spontaneous and evoked activity. Overall, our results establish the baseline response properties of lateral line primary afferent neurons in larval zebrafish, which is a crucial step in understanding how vertebrate mechanoreceptive systems sense and subsequently process information from the environment.


Author(s):  
James Deery

AbstractFor some, the states and processes involved in the realisation of phenomenal consciousness are not confined to within the organismic boundaries of the experiencing subject. Instead, the sub-personal basis of perceptual experience can, and does, extend beyond the brain and body to implicate environmental elements through one’s interaction with the world. These claims are met by proponents of predictive processing, who propose that perception and imagination should be understood as a product of the same internal mechanisms. On this view, as visually imagining is not considered to be world-involving, it is assumed that world-involvement must not be essential for perception, and thus internalism about the sub-personal basis is true. However, the argument for internalism from the unity of perception and imagination relies for its strength on a questionable conception of the relationship between the two experiential states. I argue that proponents of the predictive approach are guilty of harbouring an implicit commitment to the common kind assumption which does not follow trivially from their framework. That is, the assumption that perception and imagination are of the same fundamental kind of mental event. I will argue that there are plausible alternative ways of conceiving of this relationship without drawing internalist metaphysical conclusions from their psychological theory. Thus, the internalist owes the debate clarification of this relationship and further argumentation to secure their position.


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