Cellular activity in insular cortex across seconds to hours: Sensations and predictions of bodily states

Insular cortex (IC) receives inputs from multiple sensory systems, including taste, and from receptors that monitor body electrolyte and fluid balance and blood pressure. This work analyzed metabolic activity of IC cells after water and sodium ingestion induced by sodium depletion. Rats were injected with the diuretic furosemide (10 mg/kg body wt), followed 5 min later by injections of the angiotensin-converting enzyme inhibitor captopril (5 mg/kg body wt). After 90 min, some rats received water and 0.3 M NaCl to drink for 2 h while others did not. A third group had access to water and saline but was not depleted of fluids. All rats were killed for processing of brain tissue for Fos-immunoreactivity (Fos-ir). Nondepleted animals had weak-to-moderate levels of Fos-ir within subregions of IC. Fluid-depleted rats without fluid access had significantly increased Fos-ir in all areas of IC. Levels of Fos-ir were highest in fluid-depleted rats that drank water and sodium. Fos-ir levels were highest in anterior regions of IC and lowest in posterior regions of IC. These results implicate visceral, taste, and/or postingestional factors in the increased metabolic activity of cells in IC.

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The amygdala instructs insular feedback for affective learning

eLife ◽

10.7554/elife.60336 ◽

2020 ◽

Vol 9 ◽

Author(s):

Dominic Kargl ◽

Joanna Kaczanowska ◽

Sophia Ulonska ◽

Florian Groessl ◽

Lukasz Piszczek ◽

...

Keyword(s):

Information Flow ◽

Insular Cortex ◽

Affective Learning ◽

Affective Responses ◽

Nucleus Basalis ◽

Environmental Predictors ◽

Affective Value ◽

Psychiatric Conditions ◽

Bodily States ◽

Conditioned Responding

Affective responses depend on assigning value to environmental predictors of threat or reward. Neuroanatomically, this affective value is encoded at both cortical and subcortical levels. However, the purpose of this distributed representation across functional hierarchies remains unclear. Using fMRI in mice, we mapped a discrete cortico-limbic loop between insular cortex (IC), central amygdala (CE), and nucleus basalis of Meynert (NBM), which decomposes the affective value of a conditioned stimulus (CS) into its salience and valence components. In IC, learning integrated unconditioned stimulus (US)-evoked bodily states into CS valence. In turn, CS salience in the CE recruited these CS representations bottom-up via the cholinergic NBM. This way, the CE incorporated interoceptive feedback from IC to improve discrimination of CS valence. Consequently, opto-/chemogenetic uncoupling of hierarchical information flow disrupted affective learning and conditioned responding. Dysfunctional interactions in the IC↔CE/NBM network may underlie intolerance to uncertainty, observed in autism and related psychiatric conditions.

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The activity of discrete sets of neurons in the posterior insula correlates with the behavioral expression and extinction of conditioned fear

Journal of Neurophysiology ◽

10.1152/jn.00318.2018 ◽

2018 ◽

Vol 120 (4) ◽

pp. 1906-1913 ◽

Cited By ~ 2

Author(s):

José Patricio Casanova ◽

Marcelo Aguilar-Rivera ◽

María de los Ángeles Rodríguez ◽

Todd P. Coleman ◽

Fernando Torrealba

Keyword(s):

Conditioned Fear ◽

Insular Cortex ◽

Behavioral Expression ◽

Auditory Cue ◽

Important Player ◽

Conditioned Freezing ◽

Posterior Insula ◽

Different Populations ◽

Bodily States ◽

Fear Expression

The interoceptive insular cortex is known to be involved in the perception of bodily states and emotions. Increasing evidence points to an additional role for the insula in the storage of fear memories. However, the activity of the insula during fear expression has not been studied. We addressed this issue by recording single units from the posterior insular cortex (pIC) of awake behaving rats expressing conditioned fear during its extinction. We found a set of pIC units showing either significant increase or decrease in activity during high fear expression to the auditory cue (“freezing units”). Firing rate of freezing units showed high correlation with freezing and outlasted the duration of the auditory cue. In turn, a different set of units showed either significant increase or decrease in activity during low fear state (“extinction units”). These findings show that expression of conditioned freezing is accompanied with changes in pIC neural activity and suggest that the pIC is important to regulate the behavioral expression of fear memory. NEW & NOTEWORTHY Here, we show novel single-unit data from the interoceptive insula underlying the behavioral expression of fear. We show that different populations of neurons in the insula codify expression and extinction of conditioned fear. Our data add further support for the insula as an important player in the regulation of emotions.

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The effects of Cyclosporin-A (CYA) on the Ultrastructure of Gingival Mast Cells (GMC) in Behcet's disease (BD)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159333 ◽

1990 ◽

Vol 48 (3) ◽

pp. 358-359

Author(s):

Oktay Arda ◽

Ulkü Noyan ◽

Selgçk Yilmaz ◽

Mustafa Taşyürekli ◽

İsmail Seçkin ◽

...

Keyword(s):

Unknown Etiology ◽

Control Group ◽

Target Cells ◽

Gingival Hyperplasia ◽

Cellular Activity ◽

Direct Relation ◽

Immune Disease ◽

Genital Ulceration ◽

Functional Changes ◽

The Third

Turkish dermatologist, H. Beheet described the disease as recurrent triad of iritis, oral aphthous lesions and genital ulceration. Auto immune disease is the recent focus on the unknown etiology which is still being discussed. Among the other immunosupressive drugs, CyA included in it's treatment newly. One of the important side effects of this drug is gingival hyperplasia which has a direct relation with the presence of teeth and periodontal tissue. We are interested in the ultrastructure of immunocompetent target cells that were affected by CyA in BD.Three groups arranged in each having 5 patients with BD. Control group was the first and didn’t have CyA treatment. Patients who had CyA, but didn’t show gingival hyperplasia assembled the second group. The ones displaying gingival hyperplasia following CyA therapy formed the third group. GMC of control group and their granules are shown in FIG. 1,2,3. GMC of the second group presented initiation of supplementary cellular activity and possible maturing functional changes with the signs of increased number of mitochondria and accumulation of numerous dense cored granules next to few normal ones, FIG. 4,5,6.

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