The Brain Doesn’t Work by Logic

2018 ◽  
Author(s):  
James A. Anderson
Keyword(s):  
Lateral Inhibition ◽  
Horseshoe Crab ◽  
Compound Eye ◽  
Visual Image ◽  
Neural Computation ◽  
Single Neurons ◽  
Moving Image ◽  
Cortical Areas ◽  
Lateral Eye ◽  
The Brain

This chapter gives three examples of real neural computation. The conclusion is that the “brain doesn’t work by logic.” First, is the Limulus (horseshoe crab) lateral eye. The neural process of “lateral inhibition” tunes the neural response of the compound eye to allow crabs to better see other crabs for mating. Second, the retina of the frog contains cells that are selective to specific properties of the visual image. The frog responds strongly to the moving image of a bug with one class of selective retinal receptors. Third, experiments on patients undergoing neurosurgery for epilepsy found single neurons in several cortical areas that were highly selective to differing images, text strings, and spoken names of well-known people. In addition, new selective responses could be formed quickly. The connection to concepts in cognitive science seems inevitable. One possible mechanism is through associatively linked “cell assemblies.”

Histochemical localization of acetylcholinesterase in the lateral eye and brain of Limulus polyphemus: Might acetylcholine be a neurotransmitter for lateral inhibition in the lateral eye?

1994 ◽  
Vol 11 (5) ◽  
pp. 989-1001 ◽  
Author(s):  
Eric P. Hornstein ◽  
Daniel L. Sambursky ◽  
Steven C. Chamberlain
Keyword(s):  
Optic Nerve ◽  
Lateral Inhibition ◽  
Horseshoe Crab ◽  
Compound Eye ◽  
Nerve Fibers ◽  
Intense Staining ◽  
Histaminergic Neurons ◽  
Lateral Eye ◽  
Weak Staining ◽  
The Brain

AbstractThe distribution of acetylcholinesterase (AChE) in the lateral eye and brain of the horseshoe crab was investigated with histochemical means using standard controls to eliminate butyrylcholinesterase and nonspecific staining. Intense staining was observed in the neural plexus of the lateral compound eye, in the lateral optic nerve, and in various neuropils of the brain. Nerve fibers with moderate to weak staining were widespread in the brain. No sornata were stained in either the lateral eye or the brain. The distribution of acetylcholinesterase in the supraesophageal ganglia and nerves of the giant barnacle was also investigated for comparison. Although both the median optic nerve of the barnacle and the lateral optic nerve of the horseshoe crab appear to contain the fibers of histaminergic neurons, only the lateral optic nerve of the horseshoe crab shows AChE staining. Other parts of the barnacle nervous system, however, showed intense AChE staining. These results along with the histochemical controls eliminate the possibility that some molecule found in histaminergic neurons accounted for the AChE staining but support the possibility that acetylcholine might be involved as a neurotransmitter in lateral inhibition in the horseshoe crab retina. Two reasonable neurotransmitter candidates for lateral inhibition, histamine and acetylcholine, must now be investigated.

Visions of vision: Studies of the horseshoe crab compound eye

1992 ◽  
Vol 50 (1) ◽  
pp. 488-489
Author(s):  
Steven C. Chamberlain
Keyword(s):  
Horseshoe Crab ◽  
Light Adaptation ◽  
Compound Eye ◽  
Visually Guided ◽  
Morphological Process ◽  
Morphological Studies ◽  
Visual Processes ◽  
Lateral Eye ◽  
The Brain

The lateral eye of the horseshoe crab, Limulus polyphemus, is an important model system for studies of visual processes such as phototransduction, lateral inhibition, and light adaptation. It has also been the system of choice for pioneering studies of the role of circadian efferent input from the brain to the eye. For example, light and efferent input interact in controlling the daily shedding of photosensitive membrane and photomechanical movements. Most recently, modeling efforts have begun to relate anatomy, physiology and visually guided behavior using parallel computing. My laboratory has pursued collaborative morphological studies of the compound eye for the past 15 years. Some of this research has been correlated structure/function studies; the rest has been studies of basic morphology and morphological process.

scholarly journals A Nonlinearity in the Inhibitory Interactions in the Lateral Eye of Limulus

1974 ◽  
Vol 63 (5) ◽  
pp. 579-589 ◽  
Author(s):  
Robert B. Barlow ◽  
G. David Lange
Keyword(s):  
Steady State ◽  
Lateral Inhibition ◽  
Horseshoe Crab ◽  
Inhibitory Effect ◽  
System Of Equations ◽  
Operating Range ◽  
Lateral Eye ◽  
Inhibitory Interactions

Receptor units in the eye of the horseshoe crab are more sensitive to lateral inhibition at some levels of excitation than they are at others. As a result, the steady-state inhibition of the response of a given unit is not directly proportional to the response levels of neighboring units. This effect may be represented by the introduction of a nonlinearity in the Hartline-Ratliff system of equations. The nonlinear inhibitory effect appears to increase the operating range of the receptor units.

Anatomical circuitry of lateral inhibition in the eye of the horseshoe crab, Limulus polyphemus

1985 ◽  
Vol 225 (1239) ◽  
pp. 219-249 ◽  
Keyword(s):  
Lateral Inhibition ◽  
Synaptic Input ◽  
Horseshoe Crab ◽  
Compound Eye ◽  
Synapse Formation ◽  
Signal Transmission ◽  
Intrinsic Property ◽  
Limulus Polyphemus ◽  
Inhibitory Synapses ◽  
Retinular Cells

Lengthy uninterrupted series of sections of the neural plexus in the compound eye of the horseshoe crab, Limulus polyphemus , have been used to reconstruct all the arborizations and their synaptic interconnections in a neuropil knot. This one microglomerulus contains the axons of 19 retinular cells, which pass by without contacts; 13 efferent fibres with 44 synapses to and from eccentric cell collaterals; and arborizations from 54 eccentric cells with 577 synapses. Eccentric cell axons are devoid of synaptic input. Their collaterals ramify in synaptic knots and subserve both pre- and postsynaptic functions simultaneously. Arborizations near the axon of origin have a highly branched pattern (up to 20 bifurcations), a high synaptic input:output ratio (up to about 9:1), and high synaptic density (a maximum of 12 per micrometre of neurite length). The opposite extreme is represented by sparsely branched eccentric cell collaterals distant from their axons of origin with very little synaptic input and sparse output. Spatially graded lateral inhibition is the apparent outcome of a radially decreasing distribution of inhibitory synapses on the arborizations of eccentric cell collaterals combined with possible decremental signal transmission in the plexus. The synaptic analysis has a bearing on most physiological aspects of lateral inhibition that have been studied in the Limulus eye. Implied in the results is the suggestion that synapse formation is an intrinsic property of the presynaptic element, but that the connectivity is governed by the electrical activity of target neurons.

Orthonasal Smell

Neuroenology ◽  
2016 ◽  
pp. 80-87
Author(s):  
Gordon M. Shepherd
Keyword(s):  
Olfactory Bulb ◽  
Lateral Inhibition ◽  
Activity Pattern ◽  
Visual Image ◽  
Frontal Lobes ◽  
Olfactory Cortex ◽  
Behavioral State ◽  
Spatial Activity ◽  
Spatial Activity Pattern ◽  
The Brain

The brain creates the aroma perception through a series of steps, through the olfactory bulb to the olfactory cortex and to the highest levels in our frontal lobes. It first represents the aroma molecules as a spatial activity pattern in the olfactory bulb, virtually an “aroma image” analogous to a visual image in the brain. The smell image is enhanced by lateral inhibition, similar to contrast enhancement as we described in vision. In smell, the image can be modified depending on whether we are hungry or full. It cautions the wine taster to avoid these extremes and be in a good behavioral state.

Photoreceptor cells dissociated from the compound lateral eye of the horseshoe crab, Limulus polyphemus, II: Function

1993 ◽  
Vol 10 (4) ◽  
pp. 609-620 ◽  
Author(s):  
W. J. Brad Hanna ◽  
Edwin C. Johnson ◽  
Deborah Chaves ◽  
George H. Renninger
Keyword(s):  
Horseshoe Crab ◽  
Compound Eye ◽  
Light Response ◽  
Photoreceptor Cells ◽  
Limulus Polyphemus ◽  
Isolated Cells ◽  
Lateral Eye ◽  
Small Clusters ◽  
Invertebrate Photoreceptor

AbstractA combination of enzymatic digestions and mechanical disruption was used to isolate photoreceptor cells from the compound lateral eye of the horseshoe crab, Limulus polyphemus. The cells were maintained in a culture medium and tested for function using whole-cell and cell-attached patch configurations of the gigaseal technique. The cells dissociated from the eye generated spontaneous voltage and current bumps in the dark, and depolarized in a graded fashion to increasing intensities of light over several decades, producing responses similar to those of cells in vivo. Currents evoked during voltage clamp were similar to those in ventral photoreceptor cells of Limulus, although transient currents in the dark- and light-activated currents were smaller in isolated lateral eye cells, perhaps because of the slow speed and spatial nonuniformity of the clamp in these large cells. In addition to isolated cells, dissociation of the compound eye produced small clusters of cells and isolated ommatidia which were also tested for function. Comparison of the electrical characteristics of isolated cells with those of cells in small clusters and in their ommatidial matrix suggests that the electrical junctions normally connecting photoreceptor cells within an ommatidium are functional in the latter groups, but not in isolated cells. Cell-attached patches of rhabdomeral membrane of isolated cells contained light-activated channels, resembling those observed in ventral photoreceptor cells, but no voltage-activated channels. Similar patches of arhabdomeral membrane contained voltage-activated channels, but no light-activated channels. We conclude that this preparation is suitable for studies of processes involved in generating the light response in invertebrate photoreceptor cells.

Localization of actin filaments and microtubules in the cells of the Limulus lateral and ventral eyes

1992 ◽  
Vol 9 (3-4) ◽  
pp. 365-375 ◽  
Author(s):  
Bruce G. Calman ◽  
Steven C. Chamberlain
Keyword(s):  
Neural Activity ◽  
Actin Filaments ◽  
Horseshoe Crab ◽  
Cell Dendrite ◽  
Cell Cytoplasm ◽  
Retinular Cell ◽  
Lateral Eye ◽  
Cone Cells ◽  
Cytoskeletal Elements ◽  
The Brain

AbstractThe ommatidia of the lateral eye of the horseshoe crab, Limulus polyphemus, undergo rhythmic changes in structure that are driven by diurnal lighting and efferent neural activity from a circadian clock in the brain. This study uses cytochemical probes to investigate the cytoskeletal elements mediating these responses and to develop models for their control. Antibodies to actin and phalloidin, a specific F-actin probe, label the rhabdom of lateral eye ommatidia, the cone cells of the ommatidial aperture, the ommatidial sheath, and the peripheral regions of the photoreceptor (retinular cell) cytoplasm. These probes also label the rhabdomere of ventral photoreceptors. Antibodies to tubulin label the eccentric cell dendrite and soma in each lateral eye ommatidium, the cone cells of the aperture, and the peripheral retinular cell cytoplasm. Models are proposed for the cytoskeletal mechanisms involved in controlling aperture and rhabdom shape, pigment movement, and shedding of rhabdomeral membrane.

Visual Efference Neuromodulates Retinal Timing: In Vivo Roles of Octopamine, Substance P, Circadian Phase, and Efferent Activation in Limulus

2009 ◽  
Vol 102 (2) ◽  
pp. 1132-1138 ◽  
Author(s):  
Amanda R. Bolbecker ◽  
Corrinne C. M. Lim-Kessler ◽  
Jia Li ◽  
Alicia Swan ◽  
Adrienne Lewis ◽  
...  
Keyword(s):  
Substance P ◽  
Horseshoe Crab ◽  
Response Duration ◽  
Circadian Phase ◽  
Lateral Eye ◽  
Response Onset ◽  
Timing Effects ◽  
The Brain

Efferent nerves coursing from the brain to the lateral eye of the horseshoe crab, Limulus polyphemus, increase its nighttime sensitivity to light. They release octopamine, which produces a categorical increase of photoreceptor response duration in vitro. Analogous in vivo timing effects on the electroretinogram (ERG) were demonstrated when octopamine was infiltrated into the eye of an otherwise intact animal; nighttime ERGs were longer than daytime ERGs. Related effects on the ERG were produced by daytime electrical stimulation of efferent fibers. Surprisingly, in a departure from effects predicted solely from in vitro octopamine data, nighttime ERG onsets were also accelerated relative to daytime ERG onsets. Drawing on earlier reports, these remarkable accelerations led to an examination of substance P as another candidate neuromodulator. It demonstrated that infiltrations of either modulator into the lateral eyes of otherwise intact crabs increased the amplitude of ERG responses but that each candidate modulator induced daytime responses that specifically mimicked one of the two particular aspects of the timing differences between day- and nighttime ERGs: octopamine increased the duration of daytime ERGs and substance P infiltrated during the day accelerated response onset. These results indicate that, in addition to octopamine's known role as an efferent neuromodulator that increases nighttime ERG amplitudes, octopamine clearly also affects the timing of photoreceptor responses. But these infiltration data go further and strongly suggest that substance P may also be released into the lateral eye at night, thereby accelerating the ERG's onset in addition to increasing its amplitude.

Representations of the Texture of Food in the Primate Orbitofrontal Cortex: Neurons Responding to Viscosity, Grittiness, and Capsaicin

2003 ◽  
Vol 90 (6) ◽  
pp. 3711-3724 ◽  
Author(s):  
Edmund T. Rolls ◽  
Justus V. Verhagen ◽  
Mikiko Kadohisa
Keyword(s):  
Food Intake ◽  
Orbitofrontal Cortex ◽  
Silicone Oil ◽  
Food Selection ◽  
Single Neurons ◽  
Cortical Areas ◽  
Food Texture ◽  
A Site ◽  
The Brain ◽  
Somatosensory Cortical Areas

The primate orbitofrontal cortex (OFC) is a site of convergence from taste, olfactory, and somatosensory cortical areas. We describe a population of single neurons in the macaque OFC that responds to the texture of food in the mouth. Use of oral viscosity stimuli consisting of carboxymethylcellulose (CMC) in the range 1–10,000 centipoise showed that the responses of one subset of these neurons were related to stimulus viscosity. Some of the neurons had increasing responses to increasing viscosity, some had decreasing responses, and some neurons were tuned to a range of viscosities. These neurons are a different population to oral fat-sensitive neurons, in that their responses to fats (e.g., safflower oil), to silicone oil [(Si(CH3)2O)n], and to mineral oil (hydrocarbon) depended on the viscosity of these oils. Thus there is a dissociation between texture channels used to sense viscosity and fat. Some of these viscosity-sensitive single neurons were unimodal (somatosensory; 25%) and some received convergent taste inputs (75%). A second subpopulation of neurons responded to gritty texture (produced by microspheres suspended in CMC). A third subpopulation of neurons responded to capsaicin. These results provide evidence about the information channels used to represent the texture and flavor of food in a part of the brain important in appetitive responses to food and are relevant to understanding the physiological and pathophysiological processes related to food intake, food selection, and the effects of variety of food texture in combination with taste and other inputs that affect food intake.

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