HISTOCHEMICAL ANALYSIS OF THE NEUROSECRETORY CELLS IN THE ADULT BRAIN OF TRIPHAENA PRONUBA (LEPIDOPTERA: NOCTUIDAE)

Three types of neurosecretory cells, designated A, B, and C, occur in the central nervous system of Paratelphusa hydrodromous. They are distinguishable by their sizes, the nature of their nuclei, and the secretory products in the cytoplasm. Their distribution and neurosecretory activity are recorded in this paper. All the three types occur in the thoracic ganglion, while the brain and tritocerebral connective ganglia contain only the A and B types. Examined alive under the phase-contrast microscope, the conspicuous A-cells reveal the presence of numerous tiny granules and dark spheroids in the cytoplasm. These spheroids are stainable by neutral red. In Golgi preparations the spheroid walls become black. These are sudanophil and probably represent lipochondria. The spheroids contain phospholipid and vitamin C. The granules of the cytoplasm probably represent the mitochondria. The brain and thoracic ganglia contain within them a rich network of delicate capillaries which surround individual neurosecretory cells as well as groups of cells. The secretory products are possibly discharged directly into the blood.

The brain structure and neurosecretory cells of noctuid moth Anadevidia peponis: Noctuidae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159722 ◽

1990 ◽

Vol 48 (3) ◽

pp. 436-437

Author(s):

M. Sato ◽

Y. Ogawa ◽

M. Sasaki ◽

T. Matsuo

Keyword(s):

Biological Clock ◽

Virgin Female ◽

Basic Structure ◽

Fixed Time ◽

Neurosecretory Cells ◽

Nerve Cells ◽

Noctuid Moth ◽

The Right ◽

20 Nm ◽

The Brain

A virgin female of the noctuid moth, a kind of noctuidae that eats cucumis, etc. performs calling at a fixed time of each day, depending on the length of a day. The photoreceptors that induce this calling are located around the neurosecretory cells (NSC) in the central portion of the protocerebrum. Besides, it is considered that the female’s biological clock is located also in the cerebral lobe. In order to elucidate the calling and the function of the biological clock, it is necessary to clarify the basic structure of the brain. The observation results of 12 or 30 day-old noctuid moths showed that their brains are basically composed of an outer and an inner portion-neural lamella (about 2.5 μm) of collagen fibril and perineurium cells. Furthermore, nerve cells surround the cerebral lobes, in which NSCs, mushroom bodies, and central nerve cells, etc. are observed. The NSCs are large-sized (20 to 30 μm dia.) cells, which are located in the pons intercerebralis of the head section and at the rear of the mushroom body (two each on the right and left). Furthermore, the cells were classified into two types: one having many free ribosoms 15 to 20 nm in dia. and the other having granules 150 to 350 nm in dia. (Fig. 1).

HISTOMORPHOLOGICAL CHANGES IN THE BRAIN IN RELATION TO OVARIAN CYCLE OF FRESHWATER CRAB, BARYTELPHUSA CUNICULARIS

FLORA AND FAUNA ◽

10.33451/florafauna.v23i1pp230-236 ◽

2017 ◽

Vol 23 (1) ◽

Author(s):

C.A. JAWALE

Keyword(s):

Staining Intensity ◽

Neurosecretory Cells ◽

Ovarian Cycle ◽

Secretory Product ◽

Freshwater Crab ◽

Intensity Index ◽

Cytoplasmic Material ◽

Histomorphological Changes ◽

Cyclic Changes ◽

The Brain

Ovarian maturation by neurosecretory cells in the brain of freshwater crab, Barytelphusa cunicularis have been examined. The histological scrutiny of the brain of Barytelphusa cunicularis related with three types (A, B and C) of neurosecretory cells, which are classified on the basis of size, shape and tinctorial characters. All these types of cells marked annual cyclic changes of cytoplasmic material in association with ovarian cycle. The activity of these cells has been correlated with the ovarian cycle. They are distinguishable by their size, nature locations, shape, nucleus position, cell measure and the secretory product in the cytoplasm. The result indicates that the neurosecretory A, B and C cells of the brain seen involved in the process of mating ovulation. The neurosecretory materials staining intensity index of these cells is described.

An architectonic type principle in the development of laminar patterns of cortico-cortical connections

Brain Structure and Function ◽

10.1007/s00429-021-02219-6 ◽

2021 ◽

Author(s):

Sarah F. Beul ◽

Alexandros Goulas ◽

Claus C. Hilgetag

Keyword(s):

Structural Connectivity ◽

Macaque Monkey ◽

Brain Regions ◽

Adult Brain ◽

Mammalian Brain ◽

Cortical Connections ◽

Cortical Projections ◽

Structural Connections ◽

High Degree ◽

The Brain

AbstractStructural connections between cortical areas form an intricate network with a high degree of specificity. Many aspects of this complex network organization in the adult mammalian cortex are captured by an architectonic type principle, which relates structural connections to the architectonic differentiation of brain regions. In particular, the laminar patterns of projection origins are a prominent feature of structural connections that varies in a graded manner with the relative architectonic differentiation of connected areas in the adult brain. Here we show that the architectonic type principle is already apparent for the laminar origins of cortico-cortical projections in the immature cortex of the macaque monkey. We find that prenatal and neonatal laminar patterns correlate with cortical architectonic differentiation, and that the relation of laminar patterns to architectonic differences between connected areas is not substantially altered by the complete loss of visual input. Moreover, we find that the degree of change in laminar patterns that projections undergo during development varies in proportion to the relative architectonic differentiation of the connected areas. Hence, it appears that initial biases in laminar projection patterns become progressively strengthened by later developmental processes. These findings suggest that early neurogenetic processes during the formation of the brain are sufficient to establish the characteristic laminar projection patterns. This conclusion is in line with previously suggested mechanistic explanations underlying the emergence of the architectonic type principle and provides further constraints for exploring the fundamental factors that shape structural connectivity in the mammalian brain.

Transfer of rhodamine-123 into the brain and cerebrospinal fluid of fetal, neonatal and adult rats

Fluids and Barriers of the CNS ◽

10.1186/s12987-021-00241-8 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Liam M. Koehn ◽

Katarzyna M. Dziegielewska ◽

Mark D. Habgood ◽

Yifan Huang ◽

Norman R. Saunders

Keyword(s):

Cerebrospinal Fluid ◽

Fetal Brain ◽

Maternal Blood ◽

Adult Brain ◽

Rhodamine 123 ◽

Patient Specific ◽

Adult Rats ◽

Blood Brain ◽

The Brain ◽

Brain Barriers

Abstract Background Adenosine triphosphate binding cassette transporters such as P-glycoprotein (PGP) play an important role in drug pharmacokinetics by actively effluxing their substrates at barrier interfaces, including the blood-brain, blood-cerebrospinal fluid (CSF) and placental barriers. For a molecule to access the brain during fetal stages it must bypass efflux transporters at both the placental barrier and brain barriers themselves. Following birth, placental protection is no longer present and brain barriers remain the major line of defense. Understanding developmental differences that exist in the transfer of PGP substrates into the brain is important for ensuring that medication regimes are safe and appropriate for all patients. Methods In the present study PGP substrate rhodamine-123 (R123) was injected intraperitoneally into E19 dams, postnatal (P4, P14) and adult rats. Naturally fluorescent properties of R123 were utilized to measure its concentration in blood-plasma, CSF and brain by spectrofluorimetry (Clariostar). Statistical differences in R123 transfer (concentration ratios between tissue and plasma ratios) were determined using Kruskal-Wallis tests with Dunn’s corrections. Results Following maternal injection the transfer of R123 across the E19 placenta from maternal blood to fetal blood was around 20 %. Of the R123 that reached fetal circulation 43 % transferred into brain and 38 % into CSF. The transfer of R123 from blood to brain and CSF was lower in postnatal pups and decreased with age (brain: 43 % at P4, 22 % at P14 and 9 % in adults; CSF: 8 % at P4, 8 % at P14 and 1 % in adults). Transfer from maternal blood across placental and brain barriers into fetal brain was approximately 9 %, similar to the transfer across adult blood-brain barriers (also 9 %). Following birth when placental protection was no longer present, transfer of R123 from blood into the newborn brain was significantly higher than into adult brain (3 fold, p < 0.05). Conclusions Administration of a PGP substrate to infant rats resulted in a higher transfer into the brain than equivalent doses at later stages of life or equivalent maternal doses during gestation. Toxicological testing of PGP substrate drugs should consider the possibility of these patient specific differences in safety analysis.

Neurosecretory Cells in the Brain of the Larva of Lucilia caesar L.

Nature ◽

10.1038/179257a0 ◽

1957 ◽

Vol 179 (4553) ◽

pp. 257-258 ◽

Cited By ~ 13

Author(s):

ALASTAIR FRASER

Keyword(s):

Neurosecretory Cells ◽

The Brain

The novel guanylyl cyclase MsGC-I is strongly expressed in higher-order neuropils in the brain of Manduca sexta

Journal of Experimental Biology ◽

10.1242/jeb.204.2.305 ◽

2001 ◽

Vol 204 (2) ◽

pp. 305-314 ◽

Cited By ~ 1

Author(s):

A. Nighorn ◽

P.J. Simpson ◽

D.B. Morton

Keyword(s):

Nervous System ◽

Manduca Sexta ◽

Guanylyl Cyclase ◽

Higher Order ◽

Adult Brain ◽

Central Complex ◽

Amino Acid Residues ◽

Order Processing ◽

Guanylyl Cyclases ◽

The Brain

Guanylyl cyclases are usually characterized as being either soluble (sGCs) or receptor (rGCs). We have recently cloned a novel guanylyl cyclase, MsGC-I, from the developing nervous system of the hawkmoth Manduca sexta that cannot be classified as either an sGC or an rGC. MsGC-I shows highest sequence identity with receptor guanylyl cyclases throughout its catalytic and dimerization domains, but does not contain the ligand-binding, transmembrane or kinase-like domains characteristic of receptor guanylyl cyclases. In addition, MsGC-I contains a C-terminal extension of 149 amino acid residues. In this paper, we report the expression of MsGC-I in the adult. Northern blots show that it is expressed preferentially in the nervous system, with high levels in the pharate adult brain and antennae. In the antennae, immunohistochemical analyses show that it is expressed in the cell bodies and dendrites, but not axons, of olfactory receptor neurons. In the brain, it is expressed in a variety of sensory neuropils including the antennal and optic lobes. It is also expressed in structures involved in higher-order processing including the mushroom bodies and central complex. This complicated expression pattern suggests that this novel guanylyl cyclase plays an important role in mediating cyclic GMP levels in the nervous system of Manduca sexta.

Myf5 is a novel early axonal marker in the mouse brain and is subjected to post-transcriptional regulation in neurons

Development ◽

10.1242/dev.127.2.319 ◽

2000 ◽

Vol 127 (2) ◽

pp. 319-331 ◽

Cited By ~ 1

Author(s):

P. Daubas ◽

S. Tajbakhsh ◽

J. Hadchouel ◽

M. Primig ◽

M. Buckingham

Keyword(s):

Transcription Factor ◽

Mouse Brain ◽

Mrna Translation ◽

Adult Brain ◽

Protein Accumulation ◽

Embryonic Mouse ◽

Signalling Molecules ◽

Basic Helix Loop Helix ◽

Helix Loop Helix ◽

The Brain

Myf5 is a key basic Helix-Loop-Helix transcription factor capable of converting many non-muscle cells into muscle. Together with MyoD it is essential for initiating the skeletal muscle programme in the embryo. We previously identified unexpected restricted domains of Myf5 transcription in the embryonic mouse brain, first revealed by Myf5-nlacZ(+/)(−) embryos (Tajbakhsh, S. and Buckingham, M. (1995) Development 121, 4077–4083). We have now further characterized these Myf5 expressing neurons. Retrograde labeling with diI, and the use of a transgenic mouse line expressing lacZ under the control of Myf5 regulatory sequences, show that Myf5 transcription provides a novel axonal marker of the medial longitudinal fasciculus (mlf) and the mammillotegmental tract (mtt), the earliest longitudinal tracts to be established in the embryonic mouse brain. Tracts projecting caudally from the developing olfactory system are also labelled. nlacZ and lacZ expression persist in the adult brain, in a few ventral domains such as the mammillary bodies of the hypothalamus and the interpeduncular nucleus, potentially derived from the embryonic structures where the Myf5 gene is transcribed. To investigate the role of Myf5 in the brain, we monitored Myf5 protein accumulation by immunofluorescence and immunoblotting in neurons transcribing the gene. Although Myf5 was detected in muscle myotomal cells, it was absent in neurons. This would account for the lack of myogenic conversion in brain structures and the absence of a neural phenotype in homozygous null mutants. RT-PCR experiments show that the splicing of Myf5 primary transcripts occurs correctly in neurons, suggesting that the lack of Myf5 protein accumulation is due to regulation at the level of mRNA translation or protein stability. In the embryonic neuroepithelium, Myf5 is transcribed in differentiated neurons after the expression of neural basic Helix-Loop-Helix transcription factors. The signalling molecules Wnt1 and Sonic hedgehog, implicated in the activation of Myf5 in myogenic progenitor cells in the somite, are also produced in the viscinity of the Myf5 expression domain in the mesencephalon. We show that cells expressing Wnt1 can activate neuronal Myf5-nlacZ gene expression in dissected head explants isolated from E9.5 embryos. Furthermore, the gene encoding the basic Helix-Loop-Helix transcription factor mSim1 is expressed in adjacent cells in both the somite and the brain, suggesting that signalling molecules necessary for the activation of mSim1 as well as Myf5 are present at these different sites in the embryo. This phenomenon may be widespread and it remains to be seen how many other potentially potent regulatory genes, in addition to Myf5, when activated do not accumulate protein at inappropriate sites in the embryo.

Entry of antiepileptic drugs (valproate and lamotrigine) into the developing rat brain

F1000Research ◽

10.12688/f1000research.52607.1 ◽

2021 ◽

Vol 10 ◽

pp. 384

Author(s):

Samuel J. Toll ◽

Fiona Qiu ◽

Yifan Huang ◽

Mark D. Habgood ◽

Katarzyna M. Dziegielewska ◽

...

Keyword(s):

Antiepileptic Drug ◽

Placental Transfer ◽

Rat Plasma ◽

Developing Brain ◽

Adult Brain ◽

Cellular Mechanisms ◽

Antiepileptic Drug Treatment ◽

Dose Dependent ◽

The Brain ◽

Drug Entry

Background: Women with epilepsy face difficult choices whether to continue antiepileptic drug treatment during pregnancy, as uncontrolled seizures carry great risk to mother and fetus but continuing treatment may have adverse effects on baby’s development. This study aimed at evaluating antiepileptic drug entry into developing brain. Methods: Anaesthetised pregnant, non-pregnant adult females, postnatal and fetal rats were injected intraperitoneally with different doses, single or in combinations, of valproate and lamotrigine, all within clinical range. Injectate included 3H-labelled drug. After 30min, CSF, blood and brain samples were obtained; radioactivity was measured using liquid scintillation counting. Some animals were also exposed to valproate in feed throughout pregnancy and into neonatal period. Drug levels were measured by liquid chromatography coupled to mass spectrometry (LC-MS). Results are given as CSF or tissue/plasma% as index of drug entry. Results: Entry of valproate into brain and CSF was higher at E19 and P4 compared to adult but was not dose-dependent; placental transfer increased significantly at highest dose of 100mg/Kg. Lamotrigine entry into the brain was dose dependent only at E19. Chronic valproate treatment, or combination of valproate and lamotrigine had little effect on either drug entry, except for reduced valproate brain entry in adult brain with chronic treatment. Placental transfer decreased significantly after chronic valproate treatment. LC-MS measurement of valproate in adults confirmed that rat plasma values were within the clinical range and CSF/plasma and brain/plasma ratios for LC-MS and 3H-valproate were similar. Conclusion: Results suggest that entry of valproate may be higher in developing brain, the capacity of barrier mechanism is mostly unaffected by doses within the clinical range, with or without addition of lamotrigine. Chronic valproate exposure may result in upregulation in cellular mechanisms restricting its entry into the brain. Entry of lamotrigine was little different at different ages and was not dose dependent.