Proteolipids in developing rat brain

Abstract

In this report data are summarized on changes in the quantity of proteolipid protein (PLP), its amino acid composition, and the lipid moiety of these lipid-protein complexes in rat brain during postnatal development. In all three parts of the central nervous system (CNS) studied (cerebral hemispheres, medulla oblongata and spinal cord) the main pattern of PLP accumulation is on the whole similar. PLP content is very low in the newborn, and it increased 12 to 20-fold during development. The highest rate of PLP accumulation is observed in the period from 10 to 30 days after birth. Against the background of general similarity the concentration of some amino acids such as lysine, proline, tyrosine in PLP somewhat increased during development, while that of aspartic acid, glutamic acid, glycine, and leucine decreased. Soluble proteolipid complexes, purified to various degree from lipids were isolated from brain of rats of different ages. As compared with the original lipid extracts from which they were obtained, the crude and especially purified proteolipids in all the animals studied were enriched in acidic phospholipids (PhL). This prevalence of acidic PhL increased with age. During the development in phospholipid moiety of proteolipids (PL) the content of phosphatidyl serine, sphingomyelin and mainly diphosphatidyl glycerol increases and that of phosphatidyl inositol and especially phosphatidyl choline decreases. The concentration of acidic PhL more tightly bound with PLP appreciably increases with age. Most of these changes occur mainly during the second decade after birth.

Postnatal growth and morphological development of the brain: a species comparison

“…Using as an example the cerebellum, a late developing brain region (Levitt, 2003;Fuster, 2002) Relative volume of gray matter increases from 4-12 years of age and decreases afterwards (Pfefferbaum et al, 1994) Chimpanzee 17 Rhesus monkey 11.5 Increases in myelination and white matter until adolescence/early adulthood (Levitt, 2003;Fuster, 2002) Rat Increases in myelination and white matter until approx. 90 days (Manukian and Kirakosian, 1985) Relative volume of gray matter decreases in females in the ventral prefrontal cortex between 35 and 90 days. Such a decrease is not observed in males.…”

“…Unlike the human and non-human primates, the rat acquires little myelin prenatally but undergoes rapid postnatal myelination (Wiggins, 1982). The rat brain acquires 50% of the adult levels of myelin by PND 25 (Rodier, 1994b) and completes myelination by approximately PND 90-100 (Manukian and Kirakosian, 1985). In comparison, the human brain exhibits 50% of adult myelination status at 18 months of age; myelination is not completed until early adulthood (Rodier, 1994b).…”

“…Disappears at 2-3 months (Rakic, 1972) At birth (Howard, 1973) (Rodier, 1994b) 20-30 years of age (Levitt, 2003) Rat PND 25 (Rodier, 1994a) Majority of myelination complete at BPND 90-100 (Manukian and Kirakosian, 1985) …”

Insertion of proteolipid protein into oligodendrocyte mitochondria regulates extracellular pH and adenosine triphosphate

“…The insertion of native PLP into Olg mitochondria of animals with PLP1 / Plp1 duplications begs the question of whether native PLP is inserted into Olg mitochondria of wild‐type animals. It is well known that PLP‐mRNAs and protein increase 10–20‐fold in rodents during the first few weeks of postnatal development and are then reduced in adults (Gardinier et al, ; Manukian and Kirakosian, ). During postnatal development, the cell bodies of pre‐myelinating Olgs in postnatal cerebral cortex are intensely stained for PLP/DM20, and approximately 20% of these Olgs are apoptotic (Trapp et al, ).…”

A developmental profile of the levels of calcium pumps in chick cerebellum

“…In fact, an increase in the content of phosphatidylserine has been observed in chick corneas during embryonic development (Rintoul et al . 1984) and in purified proteolipids of developing rat brain (Manukian and Kirakosian 1985). Similarly, a progressive increase of calmodulin expression has been shown in the rat brain and other tissues during late fetal and early postnatal development (Rainteau et al .…”