Alterations in the monoamines and the synthesizing enzymes in the postnatal developmental period of the brain of Spr-/- mice

Multisensory integration (MSI) is the process that allows the brain to bind together spatiotemporally congruent inputs from different sensory modalities to produce single salient representations. While the phenomenology of MSI in vertebrate brains is well described, relatively little is known about cellular and synaptic mechanisms underlying this phenomenon. Here we use an isolated brain preparation to describe cellular mechanisms underlying development of MSI between visual and mechanosensory inputs in the optic tectum of Xenopus tadpoles. We find MSI is highly dependent on the temporal interval between crossmodal stimulus pairs. Over a key developmental period, the temporal window for MSI significantly narrows and is selectively tuned to specific interstimulus intervals. These changes in MSI correlate with developmental increases in evoked synaptic inhibition, and inhibitory blockade reverses observed developmental changes in MSI. We propose a model in which development of recurrent inhibition mediates development of temporal aspects of MSI in the tectum.

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Changes in ornithine decarboxylase and antizyme activities in developing mouse brain

Biochemical Journal ◽

10.1042/bj2500797 ◽

1988 ◽

Vol 250 (3) ◽

pp. 797-803 ◽

Cited By ~ 13

Author(s):

H Onoue ◽

S Matsufuji ◽

M Nishiyama ◽

Y Murakami ◽

S Hayashi

Keyword(s):

Monoclonal Antibodies ◽

Ornithine Decarboxylase ◽

Mouse Brain ◽

Rat Liver ◽

Developmental Period ◽

Kinetic Properties ◽

Antizyme Inhibitor ◽

Developing Mouse Brain ◽

The Brain

A macromolecular inhibitor to ornithine decarboxylase (ODC) present in mouse brain was identified as ODC antizyme [Fong, Heller & Canellakis (1976) Biochim. Biophys. Acta 428, 456-465; Heller, Fong & Canellakis (1976) Proc. Natl. Acad. Sci. U.S.A. 73, 1858-1862] on the basis of kinetic properties, Mr and reversal of its inhibition by antizyme inhibitor. The brain antizyme, however, did not cross-react immunochemically with any of seven monoclonal antibodies to rat liver antizyme. ODC activity in mouse brain rapidly decreased after birth, in parallel with putrescine content, and almost disappeared by 3 weeks of age. Free antizyme activity appeared shortly after birth and increased gradually, whereas ODC-antizyme complex already existed at birth and then gradually decreased. Thus total amount of antizyme remained about the same throughout the developmental period in mouse brain. In addition to ODC-antizyme complex, inactive ODC protein was detected by radioimmunoassay in about the same level as the complex at 3 weeks of age. Upon cycloheximide treatment, both free ODC activity and ODC-antizyme complex rapidly disappeared, although free antizyme and the inactive ODC protein were both quite stable.

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Irritability and brain volume in adolescents: cross-sectional and longitudinal associations

Social Cognitive and Affective Neuroscience ◽

10.1093/scan/nsz053 ◽

2019 ◽

Vol 14 (7) ◽

pp. 687-698 ◽

Cited By ~ 2

Author(s):

Emily L Dennis ◽

Kathryn L Humphreys ◽

Lucy S King ◽

Paul M Thompson ◽

Ian H Gotlib

Keyword(s):

Life Stress ◽

Brain Volume ◽

Externalizing Disorders ◽

Developmental Period ◽

Psychiatric Research ◽

Reactivity Index ◽

Cross Sectional ◽

Longitudinal Associations ◽

The Brain ◽

Internalizing And Externalizing

Abstract Irritability is garnering increasing attention in psychiatric research as a transdiagnostic marker of both internalizing and externalizing disorders. These disorders often emerge during adolescence, highlighting the need to examine changes in the brain and in psychological functioning during this developmental period. Adolescents were recruited for a longitudinal study examining the effects of early life stress on the development of psychopathology. The 151 adolescents (73 M/78 F, average age = 11.5 years, standard deviation = 1.1) were scanned with a T1-weighted MRI sequence and parents completed reports of adolescent irritability using the Affective Reactivity Index. Of these 151 adolescents, 94 (46 M/48 F) returned for a second session (average interval = 1.9 years, SD = 0.4). We used tensor-based morphometry to examine cross-sectional and longitudinal associations between irritability and regional brain volume. Irritability was associated with brain volume across a number of regions. More irritable individuals had larger hippocampi, insula, medial orbitofrontal cortex and cingulum/cingulate cortex and smaller putamen and internal capsule. Across the brain, more irritable individuals also had larger volume and less volume contraction in a number of areas that typically decrease in volume over the developmental period studied here, suggesting delayed maturation. These structural changes may increase adolescents’ vulnerability for internalizing and externalizing disorders.

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