Morphology of Pyramidal Neurons in the Rat Prefrontal Cortex: Lateralized Dendritic Remodeling by Chronic Stress

The prefrontal cortex (PFC) plays an important role in the stress response. We filled pyramidal neurons in PFC layer III with neurobiotin and analyzed dendrites in rats submitted to chronic restraint stress and in controls. In the right prelimbic cortex (PL) of controls, apical and distal dendrites were longer than in the left PL. Stress reduced the total length of apical dendrites in right PL and abolished the hemispheric difference. In right infralimbic cortex (IL) of controls, proximal apical dendrites were longer than in left IL, and stress eliminated this hemispheric difference. No hemispheric difference was detected in anterior cingulate cortex (ACx) of controls, but stress reduced apical dendritic length in left ACx. These data demonstrate interhemispheric differences in the morphology of pyramidal neurons in PL and IL of control rats and selective effects of stress on the right hemisphere. In contrast, stress reduced dendritic length in the left ACx.

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Positron Emission Tomographic Imaging of Serotonin Activation Effects on Prefrontal Cortex in Healthy Volunteers

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-199605000-00008 ◽

1996 ◽

Vol 16 (3) ◽

pp. 418-426 ◽

Cited By ~ 57

Author(s):

J. John Mann ◽

Kevin M. Malone ◽

David J. Diehl ◽

James Perel ◽

Thomas E. Nichols ◽

...

Keyword(s):

Prefrontal Cortex ◽

Right Hemisphere ◽

Statistical Parametric Mapping ◽

Mapping Method ◽

Anterior Cingulate ◽

Positron Emission ◽

Prolactin Response ◽

Regional Cerebral Glucose Metabolism ◽

The Right ◽

Induced Changes

Serotonergic system abnormalities have been implicated in major depression, suicide, violence, alcoholism, and other psychopathologies. The prolactin response to fenfluramine has been widely used as a neuroendocrine probe to study brain serotonin responsivity. We have extended this methodology by using the positron emission tomography (PET) 18F-fluorodeoxyglucose (18FDG) method to examine the fenfluramine-induced changes in regional cerebral glucose metabolism (rCMRglu), an indicator of changes in regional neuronal activity. We report results on 16 healthy controls, each of whom underwent two PET studies. One group of six subjects had a placebo on day 1 and a single 60 mg oral dose of fenfluramine on day 2. The second group, of 10 subjects, was tested on two consecutive occasions without drug or placebo. Data were analyzed for significant rCMRglu changes on day 2 vs day 1 using the statistical parametric mapping method ( p < 0.01). Subjects who did not receive drugs showed no statistically significant areas of rCMRglu increase or decrease on day 2 versus day 1. In contrast, the group that received fenfluramine showed significant fenfluramine-induced responses. Areas of rCMRglu increases involved mainly the left prefrontal and left temperoparietal cortex. Within the prefrontal cortex, two major areas of rCMRglu increase included, first, an area centered on the anterior cingulate and, second, an area in the lateral prefrontal cortex involving principally the inferior, middle, and superior frontal gyri. Some decreases in rCMRglu were observed, principally in the right hemisphere. This PET-fenfluramine paradigm is a potentially useful method for studying abnormalities of serotonin function in the prefrontal cortex.

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The role of prefrontal cortex in working memory: examining the contents of consciousness

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1998.0334 ◽

1998 ◽

Vol 353 (1377) ◽

pp. 1819-1828 ◽

Cited By ~ 159

Author(s):

◽

S. M. Courtney ◽

L. Petit ◽

J. V. Haxby ◽

L. G. Ungerleider

Keyword(s):

Working Memory ◽

Prefrontal Cortex ◽

Visual Processing ◽

Right Hemisphere ◽

Functional Organization ◽

Spatial Working Memory ◽

Domain Specificity ◽

Long Term Memory ◽

Present Evidence ◽

The Right

Working memory enables us to hold in our ‘mind's eye’ the contents of our conscious awareness, even in the absence of sensory input, by maintaining an active representation of information for a brief period of time. In this review we consider the functional organization of the prefrontal cortex and its role in this cognitive process. First, we present evidence from brain–imaging studies that prefrontal cortex shows sustained activity during the delay period of visual working memory tasks, indicating that this cortex maintains on–line representations of stimuli after they are removed from view. We then present evidence for domain specificity within frontal cortex based on the type of information, with object working memory mediated by more ventral frontal regions and spatial working memory mediated by more dorsal frontal regions. We also propose that a second dimension for domain specificity within prefrontal cortex might exist for object working memory on the basis of the type of representation, with analytic representations maintained preferentially in the left hemisphere and image–based representations maintained preferentially in the right hemisphere. Furthermore, we discuss the possibility that there are prefrontal areas brought into play during the monitoring and manipulation of information in working memory in addition to those engaged during the maintenance of this information. Finally, we consider the relationship of prefrontal areas important for working memory, both to posterior visual processing areas and to prefrontal areas associated with long–term memory.

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The Role of the Right Prefrontal Cortex in Self-evaluation of the Face: A Functional Magnetic Resonance Imaging Study

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2008.20024 ◽

2008 ◽

Vol 20 (2) ◽

pp. 342-355 ◽

Cited By ~ 69

Author(s):

Tomoyo Morita ◽

Shoji Itakura ◽

Daisuke N. Saito ◽

Satoshi Nakashita ◽

Tokiko Harada ◽

...

Keyword(s):

Prefrontal Cortex ◽

Face Recognition ◽

Inferior Frontal Gyrus ◽

Video Recording ◽

Imaging Study ◽

The Self ◽

Anterior Cingulate ◽

Precentral Gyrus ◽

Self Evaluation ◽

The Right

Individuals can experience negative emotions (e.g., embarrassment) accompanying self-evaluation immediately after recognizing their own facial image, especially if it deviates strongly from their mental representation of ideals or standards. The aim of this study was to identify the cortical regions involved in self-recognition and self-evaluation along with self-conscious emotions. To increase the range of emotions accompanying self-evaluation, we used facial feedback images chosen from a video recording, some of which deviated significantly from normal images. In total, 19 participants were asked to rate images of their own face (SELF) and those of others (OTHERS) according to how photogenic they appeared to be. After scanning the images, the participants rated how embarrassed they felt upon viewing each face. As the photogenic scores decreased, the embarrassment ratings dramatically increased for the participant's own face compared with those of others. The SELF versus OTHERS contrast significantly increased the activation of the right prefrontal cortex, bilateral insular cortex, anterior cingulate cortex, and bilateral occipital cortex. Within the right prefrontal cortex, activity in the right precentral gyrus reflected the trait of awareness of observable aspects of the self; this provided strong evidence that the right precentral gyrus is specifically involved in self-face recognition. By contrast, activity in the anterior region, which is located in the right middle inferior frontal gyrus, was modulated by the extent of embarrassment. This finding suggests that the right middle inferior frontal gyrus is engaged in self-evaluation preceded by self-face recognition based on the relevance to a standard self.

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Muscarinic Acetylcholine Receptor Localization on Distinct Excitatory and Inhibitory Neurons Within the ACC and LPFC of the Rhesus Monkey

Frontiers in Neural Circuits ◽

10.3389/fncir.2021.795325 ◽

2022 ◽

Vol 15 ◽

Author(s):

Alexandra Tsolias ◽

Maria Medalla

Keyword(s):

Prefrontal Cortex ◽

Muscarinic Receptors ◽

Calcium Binding ◽

Pyramidal Neurons ◽

Muscarinic Acetylcholine Receptor ◽

Anterior Cingulate ◽

Inhibitory Neurons ◽

Receptor Localization ◽

Cortical Inputs ◽

Almost All

Acetylcholine (ACh) can act on pre- and post-synaptic muscarinic receptors (mAChR) in the cortex to influence a myriad of cognitive processes. Two functionally-distinct regions of the prefrontal cortex—the lateral prefrontal cortex (LPFC) and the anterior cingulate cortex (ACC)—are differentially innervated by ascending cholinergic pathways yet, the nature and organization of prefrontal-cholinergic circuitry in primates are not well understood. Using multi-channel immunohistochemical labeling and high-resolution microscopy, we found regional and laminar differences in the subcellular localization and the densities of excitatory and inhibitory subpopulations expressing m1 and m2 muscarinic receptors, the two predominant cortical mAChR subtypes, in the supragranular layers of LPFC and ACC in rhesus monkeys (Macaca mulatta). The subset of m1+/m2+ expressing SMI-32+ pyramidal neurons labeled in layer 3 (L3) was denser in LPFC than in ACC, while m1+/m2+ SMI-32+ neurons co-expressing the calcium-binding protein, calbindin (CB) was greater in ACC. Further, we found between-area differences in laminar m1+ dendritic expression, and m2+ presynaptic localization on cortico-cortical (VGLUT1+) and sub-cortical inputs (VGLUT2+), suggesting differential cholinergic modulation of top-down vs. bottom-up inputs in the two areas. While almost all inhibitory interneurons—identified by their expression of parvalbumin (PV+), CB+, and calretinin (CR+)—expressed m1+, the localization of m2+ differed by subtype and area. The ACC exhibited a greater proportion of m2+ inhibitory neurons compared to the LPFC and had a greater density of presynaptic m2+ localized on inhibitory (VGAT+) inputs targeting proximal somatodendritic compartments and axon initial segments of L3 pyramidal neurons. These data suggest a greater capacity for m2+-mediated cholinergic suppression of inhibition in the ACC compared to the LPFC. The anatomical localization of muscarinic receptors on ACC and LPFC micro-circuits shown here contributes to our understanding of diverse cholinergic neuromodulation of functionally-distinct prefrontal areas involved in goal-directed behavior, and how these interactions maybe disrupted in neuropsychiatric and neurological conditions.

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Gene expression profiling of the dorsolateral and medial orbitofrontal cortex in schizophrenia

Translational Neuroscience ◽

10.1515/tnsci-2016-0021 ◽

2016 ◽

Vol 7 (1) ◽

Cited By ~ 4

Author(s):

Mihovil Mladinov ◽

Goran Sedmak ◽

Heidi R. Fuller ◽

Mirjana Babić Leko ◽

Davor Mayer ◽

...

Keyword(s):

Gene Expression ◽

Prefrontal Cortex ◽

Cognitive Processing ◽

Orbitofrontal Cortex ◽

Right Hemisphere ◽

Transcriptome Profiling ◽

Differentially Expressed ◽

Unknown Etiology ◽

Dorsolateral Prefrontal ◽

The Right

AbstractSchizophrenia is a complex polygenic disorder of unknown etiology. Over 3,000 candidate genes associated with schizophrenia have been reported, most of which being mentioned only once. Alterations in cognitive processing - working memory, metacognition and mentalization - represent a core feature of schizophrenia, which indicates the involvement of the prefrontal cortex in the pathophysiology of this disorder. Hence we compared the gene expression in postmortem tissue from the left and right dorsolateral prefrontal cortex (DLPFC, Brodmann's area 46), and the medial part of the orbitofrontal cortex (MOFC, Brodmann's area 11/12), in six patients with schizophrenia and six control brains. Although in the past decade several studies performed transcriptome profiling in schizophrenia, this is the first study to investigate both hemispheres, providing new knowledge about possible brain asymmetry at the level of gene expression and its relation to schizophrenia. We found that in the left hemisphere, twelve genes from the DLPFC and eight genes from the MOFC were differentially expressed in patients with schizophrenia compared to controls. In the right hemisphere there was only one gene differentially expressed in the MOFC. We reproduce the involvement of previously reported genes TARDBP and HNRNPC in the pathogenesis of schizophrenia, and report seven novel genes:

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Dendritic right/left asymmetries in the neurons of the human hippocampal formation: a quantitative Golgi study

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2007000700003 ◽

2007 ◽

Vol 65 (4b) ◽

pp. 1105-1113 ◽

Cited By ~ 5

Author(s):

Maria José Sá ◽

Carlos Ruela ◽

Maria Dulce Madeira

Keyword(s):

Pyramidal Neurons ◽

Right Hemisphere ◽

Granule Cells ◽

Hippocampal Formation ◽

Molecular Layer ◽

Pyramidal Cells ◽

Volumetric Analysis ◽

Golgi Study ◽

Dendritic Trees ◽

The Right

OBJECTIVE: To search for right/left asymmetries in the dendritic trees of the neuronal populations and in the cell-free layer volumes of the human hipoccampal formation. METHOD: In necropsic material obtained from six male individuals we performed a quantitative Golgi study of the dendritic trees of dentate granules, CA3 and CA1 pyramidal neurons and a volumetric analysis of dentate gyrus molecular layer, strata oriens plus alveus and strata lacunosum-moleculare plus radiatum of CA3 and CA1 fields. RESULTS: We found inter-hemispheric asymmetries in the dendrites trees of all neurons, reaching the significant level in the number of granule cells dendritic segments (higher in the left than in the right hemisphere), dendritic branching density of CA3 pyramidal cells and mean dendritic length of CA1 apical terminal segments (higher in the right than in the opposite side). No volumetric differences were observed. CONCLUSION: This study points to different anatomical patterns of connectivity in the hippocampal formations of both hemispheres which may underlie functional asymmetries.

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Medial Cortical Structures Mediate Implicit Trustworthiness Judgments about Kin Faces, but Not Familiar Faces: A Brief Report

Psych ◽

10.3390/psych1010037 ◽

2019 ◽

Vol 1 (1) ◽

pp. 482-490 ◽

Cited By ~ 1

Author(s):

Steven M. Platek ◽

Judson C. Hendry

Keyword(s):

Right Hemisphere ◽

Kin Recognition ◽

Insular Cortex ◽

Neural Correlates ◽

The Self ◽

Anterior Cingulate ◽

Dorsal Anterior Cingulate Cortex ◽

Facial Stimuli ◽

The Right ◽

Processing Network

Human kin recognition activates substrates of the extended facial processing network, notably the right-hemisphere structures involved in self-face recognition and posterior medial cortical substrates. To understand the mechanisms underlying prosociality toward kin faces in comparison to other familiar faces, we investigated the neural correlates of implicit trustworthiness ratings to faces of actual kin and personal friends, controlling for activation to distracter faces. When controlling for activation associated with unknown faces, trustworthiness ratings of faces of kin, compared to friends, were associated with increased activation in the dorsal anterior cingulate cortex, posterior cingulate, and precuneous. On the other hand, trustworthiness ratings of friend faces, relative to kin faces, were associated with the lateral occipital gyrus and insular cortex. Trustworthiness ratings for unknown faces were only associated with activation in the fusiform gyrus. These findings suggest that we should employ medial cortical substrates known to be part of the self-other network when making implicit social judgements about kin, but not other classes of facial stimuli.

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Anatomy of Motor Learning. I. Frontal Cortex and Attention to Action

Journal of Neurophysiology ◽

10.1152/jn.1997.77.3.1313 ◽

1997 ◽

Vol 77 (3) ◽

pp. 1313-1324 ◽

Cited By ~ 411

Author(s):

M. Jueptner ◽

K. M. Stephan ◽

C. D. Frith ◽

D. J. Brooks ◽

R.S.J. Frackowiak ◽

...

Keyword(s):

Prefrontal Cortex ◽

Motor Learning ◽

Frontal Cortex ◽

Anterior Cingulate Cortex ◽

Cingulate Cortex ◽

Anterior Cingulate ◽

Critical Feature ◽

Positron Emission ◽

New Learning ◽

The Right

Jueptner, M., K. M. Stephan, C. D. Frith, D. J. Brooks, R.S.J. Frackowiak, and R. E. Passingham. Anatomy of motor learning. I. Frontal cortex and attention to action. J. Neurophysiol. 77: 1313–1324, 1997. We used positron emission tomography to study new learning and automatic performance in normal volunteers. Subjects learned sequences of eight finger movements by trial and error. In a previous experiment we showed that the prefrontal cortex was activated during new learning but not during automatic performance. The aim of the present experiment was to see what areas could be reactivated if the subjects performed the prelearned sequence but were required to pay attention to what they were doing. Scans were carried out under four conditions. In the first the subjects performed a prelearned sequence of eight key presses; this sequence was learned before scanning and was practiced until it had become overlearned, so that the subjects were able to perform it automatically. In the second condition the subjects learned a new sequence during scanning. In a third condition the subjects performed the prelearned sequence, but they were required to attend to what they were doing; they were instructed to think about the next movement. The fourth condition was a baseline condition. As in the earlier study, the dorsal prefrontal cortex and anterior cingulate area 32 were activated during new learning, but not during automatic performance. The left dorsal prefrontal cortex and the right anterior cingulate cortex were reactivated when subjects paid attention to the performance of the prelearned sequence compared with automatic performance of the same task. It is suggested that the critical feature was that the subjects were required to attend to the preparation of their responses. However, the dorsal prefrontal cortex and the anterior cingulate cortex were activated more when the subjects learned a new sequence than they were when subjects simply paid attention to a prelearned sequence. New learning differs from the attention condition in that the subjects generated moves, monitored the outcomes, and remembered the responses that had been successful. All these are nonroutine operations to which the subjects must attend. Further analysis is needed to specify which are the nonroutine operations that require the involvement of the dorsal prefrontal and anterior cingulate cortex.

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Asymmetries in numerical density of pyramidal neurons in the fifth layer of the human posterior parietal cortex

Vojnosanitetski pregled ◽

10.2298/vsp101126016d ◽

2012 ◽

Vol 69 (8) ◽

pp. 681-685

Author(s):

Natasa Djukic-Macut ◽

Slobodan Malobabic ◽

Natalija Stefanovic ◽

Predrag Mandic ◽

Tatjana Filipovic ◽

...

Keyword(s):

Parietal Cortex ◽

Posterior Parietal Cortex ◽

Pyramidal Neurons ◽

Right Hemisphere ◽

Numerical Density ◽

Group I ◽

Posterior Parietal ◽

Left And Right ◽

Layer V ◽

The Right

Background/Aim. Both superior parietal lobule (SPL) of dorsolateral hemispheric surface and precuneus (PEC) of medial surface are the parts of posterior parietal cortex. The aim of this study was to determine the numerical density (NV) of pyramidal neurons in the layer V of SPL and PEC and their potential differences. Methods. From 20 (40 hemispheres) formaline fixed human brains (both sexes; 27- 65 years) tissue blocks from SPL and PEC from the left and right hemisphere were used. According to their size the brains were divided into two groups, the group I with the larger left (15 brains) and the group II with the larger right hemisphere (5 brains). Serial Nissl sections (5 ?m) of the left and right SPL and PEC were used for stereological estimation of NV of the layer V pyramidal neurons. Results. NV of pyramidal neurons in the layer V in the left SPL of brains with larger left hemispheres was significantly higher than in the left SPL of brains with larger right hemisphere. Comparing sides in brains with larger left hemisphere, the left SPL had higher NV than the right one, and then the left PEC, and the right SPL had significantly higher NV than the right PEC. Comparing sides in brains with the larger right hemisphere, the left SPL had significantly higher NV than left PEC, but the right SPL had significantly higher NV than left SPL and the right PEC. Conclusion. Generally, there is an inverse relationship of NV between the medial and lateral areas of the human posterior parietal cortex. The obtained values were different between the brains with larger left and right hemispheres, as well as between the SPL and PEC. In all the comparisons the left SPL had the highest values of NV of pyramidal neurons in the layer V (4771.80 mm-3), except in brains with the larger right hemisphere.

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Optical Mapping of Brain Activity Underlying Directionality and Its Modulation by Expertise in Mandarin/English Interpreting

Frontiers in Human Neuroscience ◽

10.3389/fnhum.2021.649578 ◽

2021 ◽

Vol 15 ◽

Author(s):

Yan He ◽

Yinying Hu ◽

Yaxi Yang ◽

Defeng Li ◽

Yi Hu

Keyword(s):

Prefrontal Cortex ◽

Cognitive Skills ◽

Near Infrared ◽

Right Hemisphere ◽

Brain Activity ◽

Brain Regions ◽

Broca’S Area ◽

Broca's Area ◽

Functional Near Infrared Spectroscopy ◽

The Right

Recent neuroimaging research has suggested that unequal cognitive efforts exist between interpreting from language 1 (L1) to language 2 (L2) compared with interpreting from L2 to L1. However, the neural substrates that underlie this directionality effect are not yet well understood. Whether directionality is modulated by interpreting expertise also remains unknown. In this study, we recruited two groups of Mandarin (L1)/English (L2) bilingual speakers with varying levels of interpreting expertise and asked them to perform interpreting and reading tasks. Functional near-infrared spectroscopy (fNIRS) was used to collect cortical brain data for participants during each task, using 68 channels that covered the prefrontal cortex and the bilateral perisylvian regions. The interpreting-related neuroimaging data was normalized by using both L1 and L2 reading tasks, to control the function of reading and vocalization respectively. Our findings revealed the directionality effect in both groups, with forward interpreting (from L1 to L2) produced more pronounced brain activity, when normalized for reading. We also found that directionality was modulated by interpreting expertise in both normalizations. For the group with relatively high expertise, the activated brain regions included the right Broca’s area and the left premotor and supplementary motor cortex; whereas for the group with relatively low expertise, the activated brain areas covered the superior temporal gyrus, the dorsolateral prefrontal cortex (DLPFC), the Broca’s area, and visual area 3 in the right hemisphere. These findings indicated that interpreting expertise modulated brain activation, possibly because of more developed cognitive skills associated with executive functions in experienced interpreters.

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