Erratum to: Decreased pyramidal neuron size in Brodmann areas 44 and 45 in patients with autism

OBJECTIVEThe purpose of this study was to investigate the morphology, connectivity, and correlative anatomy of the longitudinal group of fibers residing in the frontal area, which resemble the anterior extension of the superior longitudinal fasciculus (SLF) and were previously described as the frontal longitudinal system (FLS).METHODSFifteen normal adult formalin-fixed cerebral hemispheres collected from cadavers were studied using the Klingler microdissection technique. Lateral to medial dissections were performed in a stepwise fashion starting from the frontal area and extending to the temporoparietal regions.RESULTSThe FLS was consistently identified as a fiber pathway residing just under the superficial U-fibers of the middle frontal gyrus or middle frontal sulcus (when present) and extending as far as the frontal pole. The authors were able to record two different configurations: one consisting of two distinct, parallel, longitudinal fiber chains (13% of cases), and the other consisting of a single stem of fibers (87% of cases). The fiber chains’ cortical terminations in the frontal and prefrontal area were also traced. More specifically, the FLS was always recorded to terminate in Brodmann areas 6, 46, 45, and 10 (premotor cortex, dorsolateral prefrontal cortex, pars triangularis, and frontal pole, respectively), whereas terminations in Brodmann areas 4 (primary motor cortex), 47 (pars orbitalis), and 9 were also encountered in some specimens. In relation to the SLF system, the FLS represented its anterior continuation in the majority of the hemispheres, whereas in a few cases it was recorded as a completely distinct tract. Interestingly, the FLS comprised shorter fibers that were recorded to interconnect exclusively frontal areas, thus exhibiting different fiber architecture when compared to the long fibers forming the SLF.CONCLUSIONSThe current study provides consistent, focused, and robust evidence on the morphology, architecture, and correlative anatomy of the FLS. This fiber system participates in the axonal connectivity of the prefrontal-premotor cortices and allegedly subserves cognitive-motor functions. Based in the SLF hypersegmentation concept that has been advocated by previous authors, the FLS should be approached as a distinct frontal segment within the superior longitudinal system.

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Faculty Opinions recommendation of LTP is accompanied by an enhanced local excitability of pyramidal neuron dendrites.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1017223.202352 ◽

2004 ◽

Author(s):

Leonard Maler

Keyword(s):

Pyramidal Neuron

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Episodic Memory Encoding and Retrieval in Face-Name Paired Paradigm: An fNIRS Study

Brain Sciences ◽

10.3390/brainsci11070951 ◽

2021 ◽

Vol 11 (7) ◽

pp. 951

Author(s):

Qian Yu ◽

Boris Cheval ◽

Benjamin Becker ◽

Fabian Herold ◽

Chetwyn C. H. Chan ◽

...

Keyword(s):

Episodic Memory ◽

Neural Activity ◽

Near Infrared ◽

Clinical Settings ◽

Functional Near Infrared Spectroscopy ◽

Associate Learning ◽

Brodmann Areas ◽

Parietal Cortices ◽

Increased Activity ◽

Encoding And Retrieval

Background: Episodic memory (EM) is particularly sensitive to pathological conditions and aging. In a neurocognitive context, the paired-associate learning (PAL) paradigm, which requires participants to learn and recall associations between stimuli, has been used to measure EM. The present study aimed to explore whether functional near-infrared spectroscopy (fNIRS) can be employed to determine cortical activity underlying encoding and retrieval. Moreover, we examined whether and how different aspects of task (i.e., novelty, difficulty) affects those cortical activities. Methods: Twenty-two male college students (age: M = 20.55, SD = 1.62) underwent a face-name PAL paradigm under 40-channel fNIRS covering fronto-parietal and middle occipital regions. Results: A decreased activity during encoding in a broad network encompassing the bilateral frontal cortex (Brodmann areas 9, 11, 45, and 46) was observed during the encoding, while an increased activity in the left orbitofrontal cortex (Brodmann area 11) was observed during the retrieval. Increased HbO concentration in the superior parietal cortices and decreased HbO concentration in the inferior parietal cortices were observed during encoding while dominant activation of left PFC was found during retrieval only. Higher task difficulty was associated with greater neural activity in the bilateral prefrontal cortex and higher task novelty was associated with greater activation in occipital regions. Conclusion: Combining the PAL paradigm with fNIRS provided the means to differentiate neural activity characterising encoding and retrieval. Therefore, the fNIRS may have the potential to complete EM assessments in clinical settings.

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Suppression of pyramidal neuron G protein-gated inwardly rectifying K+ channel signaling impairs prelimbic cortical function and underlies stress-induced deficits in cognitive flexibility in male, but not female, mice

Neuropsychopharmacology ◽

10.1038/s41386-021-01063-w ◽

2021 ◽

Author(s):

Eden M. Anderson ◽

Steven Loke ◽

Benjamin Wrucke ◽

Annabel Engelhardt ◽

Skyler Demis ◽

...

Keyword(s):

G Protein ◽

Cognitive Flexibility ◽

Pyramidal Neuron ◽

K Channel ◽

Cortical Function ◽

Female Mice ◽

Inwardly Rectifying

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3D Ultrastructure of Synaptic Inputs to Distinct GABAergic Neurons in the Mouse Primary Visual Cortex

Cerebral Cortex ◽

10.1093/cercor/bhaa378 ◽

2020 ◽

Author(s):

Yang-Sun Hwang ◽

Catherine Maclachlan ◽

Jérôme Blanc ◽

Anaëlle Dubois ◽

Carl C H Petersen ◽

...

Keyword(s):

Visual Cortex ◽

Primary Visual Cortex ◽

Pyramidal Neuron ◽

Cell Types ◽

Gabaergic Neurons ◽

Inhibitory Synapses ◽

Synaptic Inputs ◽

Neuronal Types ◽

The Difference ◽

Ultrastructure Of Synapses

Abstract Synapses are the fundamental elements of the brain’s complicated neural networks. Although the ultrastructure of synapses has been extensively studied, the difference in how synaptic inputs are organized onto distinct neuronal types is not yet fully understood. Here, we examined the cell-type-specific ultrastructure of proximal processes from the soma of parvalbumin-positive (PV+) and somatostatin-positive (SST+) GABAergic neurons in comparison with a pyramidal neuron in the mouse primary visual cortex (V1), using serial block-face scanning electron microscopy. Interestingly, each type of neuron organizes excitatory and inhibitory synapses in a unique way. First, we found that a subset of SST+ neurons are spiny, having spines on both soma and dendrites. Each of those spines has a highly complicated structure that has up to eight synaptic inputs. Next, the PV+ and SST+ neurons receive more robust excitatory inputs to their perisoma than does the pyramidal neuron. Notably, excitatory synapses on GABAergic neurons were often multiple-synapse boutons, making another synapse on distal dendrites. On the other hand, inhibitory synapses near the soma were often single-targeting multiple boutons. Collectively, our data demonstrate that synaptic inputs near the soma are differentially organized across cell types and form a network that balances inhibition and excitation in the V1.

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