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PubMed1984

Neurophysin heterogeneity. Difference between newly formed and aged neurosecretory granules.

Neurosecretory granules from bovine neurohypophyses were isolated on iso-osmotic gradients. The content of the granules was analyzed by analytical and two-dimensional gel electrophoreses. The distributions in the gels of vasopressin precursor and neurophysins were detected by radioimmunoassays. Analytical gel electrophoresis of the content of a crude granule preparation showed the presence of different populations of neurophysin molecules. Further analysis demonstrated that vasopressin-neurophysin and oxytocin-neurophysin can be subdivided into molecules with different pI values. Whereas newly formed granules showed two main spots of neurophysin with pI of 5.0 and 5.6, aged granules contain in addition to these different populations of neurophysin-like material, some of which had a basic pI. Vasopressin precursor activity was detected in spots containing proteins with acidic pI and Mr approximately 18,000 and also in proteins of Mr = 8,000-10,000 migrating in the basic region of the gel. The results suggest that in the neural lobe there is an aging process which gives rise to several subpopulations of neurophysins. The different forms of vasopressin-associated bovine neurophysin and oxytocin-associated bovine neurophysin are only found in the granules which are not required for release.

Animals↗
PubMed1980

Identification and metabolic differentiation of rat neurophysins: a microelectrophoretic study.

Proteins of the hypothalamo-neurohypophysial system of the rat were studied by means of a purpose-modified form of microelectrophoresis in the polyacrylamide gradient. The respective shares of neurophysins I, II and III in total neurophysin were found to be 58 +/- 16, 24 +/- 5 and 18 +/- 6% in HCl extracts and 48 +/- 7, 30 +/- 7 and 23 +/- 5% in aqueous extracts. In particular, neurophysin I was absent in homozygous Brattleboro rats, with no evidence being obtained as to aberrant neurophysins. Approximately equal neurophysin shares were observed for heterozygous Brattleboro rats. Using perfused material, one of the fractions occurring in neurohypophysial extracts was clearly identified as serum albumin. The electropherograms of aqueous neurohypophysial extracts revealed up to 43 protein fractions. Comparison with extracts from the median eminence, the nuclei of the hypothalamo-neurohyophysial system and other hypothalamic regions, as well as the results of incubation experiments distinguished one fraction as a possible candidate for the hitherto hypothetical neurophysin precursors. Incubation of neurohypophyses did not yield any signs of both conversion of neurophysin II into neurophysin III, and formation of further neurophysin derivatives.

Animals↗
PubMed1986

Precursors of mesotocin and vasotocin in birds: identification of VLDV- and MSEL- neurophysins in chicken, goose, and ostrich.

Precursors of neurohypophysial hormones are small proteins processed into nonapeptide hormones and neurophysins during axonal transport to the neurohypophysis. In mammals, oxytocin is associated with VLDV-neurophysin and vasopressin with MSEL-neurophysin. In birds, mesotocin and vasotocin are found instead of mammalian oxytocin and vasopressin. From goose, chicken and ostrich posterior pituitary glands, two types of neurophysins related to mammalian VLDV- and MSEL-neurophysins, respectively, have been identified by their N-terminal sequences. It is assumed that, as in mammals, hormonal peptide and the first 9 residues of the corresponding neurophysin are encoded by a common exon and that mesotocin and vasotocin, evolutionary predecessors of oxytocin and vasopressin, are associated in the precursors with VLDV-neurophysin and MSEL-neurophysin, respectively.

Amino Acid Sequence↗
PubMed1980

Purification of porcine neurophysins I and II by high performance liquid chromatography.

Porcine neurophysins I and II have been reported to be metabolically active. This activity was suggested to be due to contaminations. Furthermore, neurophysin I has been suggested to be heterogeneous on the basis of amino acid sequence analysis. The neurophysins I and II were isolated from porcine pituitary glands. Though they seemed homogeneous in polyacrylamide gel- and sodium dodecyl sulfate electrophoresis, neurophysin I could be separated into neurophysin I1 and I2 by high performance liquid chromatography. Neurophysin I2 differs from neurophysin I1 by one additional C-terminal amino acid. The purified neurophysins had no metabolic activity.

Amino Acid Sequence↗
PubMed1988

Structure, processing and evolution of the neurohypophysial hormone-neurophysin precursors.

Neurohypophysial hormones and neurophysins are derived from common precursors processed during the axonal transport from the hypothalamus to the neurohypophysis. Two neurohormones, an oxytocin-like and a vasopressin-like, on one hand, two neurophysins, termed VLDV-and MSEL-neurophysins according to residues in positions 2, 3, 6 and 7, on the other, are usually found in vertebrate species. In contrast to placental mammals that have oxytocin and arginine vasopressin, marsupials have undergone a peculiar evolution. Two pressor peptides, lysipressin and vasopressin for American species, lysipressin and phenylpressin for Australian macropods, have been identified in individual glands and it is assumed that the primordial vasopressin gene has been duplicated in these lineages. On the other hand, the reptilian mesotocin is still present in Australian species instead of the mammalian oxytocin, while the North American opossum has both hormones and South American opossums have only oxytocin. The neurophysin domain of each precursor is encoded by 3 exons and different evolutionary rates have been found for the 3 corresponding parts of the protein. The central parts, encoded by the central exons, are evolutionarily very stable and nearly identical in the 2 neurophysins of a given species. Recurrent gene conversions have apparently linked the evolutions of the 2 precursor lineages. In mammals, the 3-domain precursor of vasopressin is processed in 2 stages: a first cleavage splitting off vasopressin and a second cleavage separating MSEL-neurophysin from copeptin. Two distinct enzymatic systems seem to be involved in these cleavages. Processing is usually complete at the level of the neurohypophysis, but an intermediate precursor encompassing MSEL -neurophysin and copeptin linked by an arginine residue has been characterized in guinea pig. In vitro processing of this intermediate through trypsin--Sepharose reveals cleavages only in the interdomain region. In non-mammalian tetrapods, such as birds and amphibians, mesotocin and vasotocin are associated with neurophysins in precursors similar to those found in mammals. However, processing of the vasotocin precursor seems to be different from the processing of the vasopressin precursor, with a single cleavage leading to the hormone release.

Amino Acid Sequence↗
PubMed1988

The neurophysin-containing innervation of the forebrain of the mouse.

The oxytocinergic and vasopressinergic innervation of the forebrain of normal mice was studied immunocytochemically by use of a set of mouse monoclonal anti-neurophysins applied to serial vibratome sections. The extensive hypothalamic and extra-hypothalamic location of these neuropeptides was revealed, with, or without colchicine pretreatment. Magnocellular perikarya immunoreactive for either oxytocin-neurophysin or vasopressin-neurophysin were concentrated mainly: in the anterior commissural nucleus; in various subdivisions of the paraventricular nucleus; in a profuse array in the periventricular region; in the supraoptic nucleus including its retrochiasmatic division; in various accessory nuclei; and as a number of cells scattered throughout the preoptic and hypothalamic regions. Extensive groups of parvocellular neurons, containing only vasopressin-neurophysin, were located in the suprachiasmatic nucleus including a ventromedial division, in the bed nucleus of the stria terminalis, and in the medial amygdaloid nucleus. Perikarya in the magnocellular nuclei were of generally similar size distribution and there was no evidence that distinct populations of magnocellular and parvicellular neurons, separable on the basis of size, had been labelled within these nuclei. Within the paraventricular nucleus, however, neurons in the posterior part were smaller than those located more anteriorly, and the cells containing oxytocin-neurophysin were slightly smaller than those containing vasopressin-neurophysin. Within the generally similar size distribution, magnocellular neurons of the anterior commissural nucleus were the largest. During processing, shrinkage of the tissue and immunolabeled cells had occurred. The immunocytochemical procedure delineated neuronal processes, in particular dendrites, very effectively. The dendrites were shown to project for far greater distances than is generally recognized, some were of a characteristic corkscrew-like morphology, and most were oriented in a well-defined pattern. Many dendrites of paraventricular neurons passed medially than caudally towards and then along the third ventricle. Most dendrites of supraoptic neurons, in particular those containing vasopressin-neurophysin, had an extensive anteroposterior course beneath the pia of the base of the brain. The axons containing oxytocin- and vasopressin-neurophysin were shown to take rather different paths from the paraventricular nucleus towards the median eminence.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

End-group modified retro-inverso isomers of tripeptide oxytocin analogues: binding to neurophysin II and enhancement of its self-association properties.

The importance of peptide backbone structure in peptide/protein recognition events has been tested evaluating the binding properties of end-group modified retro-inverso isomers of MYF and LYF amides, tripeptides able to mimic oxytocin in binding neurophysin II and in potentiating its self-association. The isomers, topochemically related to their parent peptides, have been prepared respectively from all-D N-acetyl-FYM and N-acetyl-FYL amides via the Hofmann-type rearrangement mediated by iodobenzene bis-trifluoroacetate. Retro-inverso isomers recognised neurophysin II with similar affinity as the parent peptides, as determined by analytical affinity chromatography on columns prepared immobilising neurophysin II on preactivated supports. In addition, their effect on neurophysin II self-association was similar to the tripeptide oxytocin analogues, potentiating neurophysin II dimerization to the same extent, as evaluated by solid-phase binding assays on microtiter plates coated with neurophysin II. Recognition specificity of retro-inverso isomers was further demonstrated by their inhibitory effect on the interaction between neurophysin II and oxytocin tripeptide analogues. Results suggest that only the proper orientation of the alpha-amino group and of the side chains plays a dominant role in the binding of tripeptide analogues to neurophysin II and potentiation of its self-association, while the peptide backbone topology has little influence on the recognition process.

Amino Acid Sequence↗
PubMed1975

Some properties of neurophysins isolated from bovine neurosecretory granules.

Our experiments with the neurophysin-related proteins from bovine NSG have demonstrated that these species differ in several important respects from the materials conventionally prepared. (1) In structural terms, the NSG proteins are essentially identical with the conventional neurophysins in amino acid composition and closely similar in immunoreactivity; however, the presence of carbodydrate and lipid moieties in the NSG material, no matter how they are attached, constitutes a structural difference apparently sufficient to cause considerable changes in properties. (2) The affinities for the neurohypophyseal hormones of the NSG proteins are very much higher than those of the "conventional" neurophysins and, moreover, the binding properties of the NSG material are much more stable with time under the conditions of the binding experiments. (3) The low binding capacities of the NSG materials, even when they are purified to apparent molecular homogeneity, indicate a functional heterogeneity perhaps related to supramolecular structure. (4) The conversion of the NSG proteins by acid or alkali treatment to materials resembling the "conventional" neurophysins in their binding properties suggests that the latter may be isolation artifacts. Although we cannot as yet consistently explain the properties of our neurophysins from NSG, we offer the hypothesis that the low binding capacity, as also the Hill coefficient greater than 1 (cf. Reference 25) are indicative of molecular aggregation, perhaps mediated or facilitated by the nonprotein components. It is conceivable that such aggregation, proceeding in the more "natural" environment of the NSG in a more precisely organized manner, might constitute the truly "native," fully functional state of the neurophysins. In this context it is of interest to record our preliminary observations, which suggest the presence of a protein of 10,000 mol. wt. in the NSG membrane fraction (SDS gel) as well as electron-microscopic indications30 of a highly organized ("crystalline") structure within these membranes. Although, therefore, the materials we have described may not merit the description of "native" neurophysins, we believe that they are certainly closer to the native state than the proteins conventionally isolated; and we would suggest that any discussion of the biological role of the neurophysins based on the properties of the conventional preparations may be at best speculative, and at worst misleading.

Amino Acids↗
PubMed1978

Serum Neurophysins in familial central diabetes insipidus.

Antibovine neurophysin antibodies (anti-bNpI and/or anti-bNpII) are present in certain patients with familial central diabetes insipidus; these are exogenous origin, as they are not present in patients who have not received treatment with crude posterior pituitary extracts over the years preceding the analysis. Immunoreactive neurophysins were detectable in the blood of five patients with familial central diabetes insipidus, and in two of them, the levels increased after a short period of water restriction. There is marked polymorphism of these neurophysins from one serum to another: neurophysin I was consistently absent, while neurophysin II, accessory neurophysins, and other immunoreactive substances not present in normal sera were sometimes present in variable amounts. Immunoreactive AVP was undetectable in the urine of all patients, while immunoreactive OT was found in three of them; the latter substance could, however, be arginine vasotocin. Data are presented suggesting that the association between the biosynthesis of neurophysin I and AVP on the one hand, and neurophysin II and OT on the other hand is maintained in patients with isolated AVP deficiency on the basis of a congenital defect.

Adolescent↗
PubMed1989

Bovine neurophysin-II stimulates prolactin release without involvement of dopaminergic prolactin-release inhibiting factor receptor in the estradiol-primed male rat.

Neurophysins have been considered to be physiologically inert carrier proteins for the neurohypophysial hormones, oxytocin and vasopressin. We have observed that bovine neurophysin-II indirectly stimulates prolactin release in estradiol-primed male rats. The release of prolactin is regulated by a dual hypothalamic control system, the prolactin-release-inhibiting factor and the prolactin-releasing factor. We have tried to clarify whether neurophysin-II is acting through stimulation of prolactin-releasing factor by eliminating the possibility of dopaminergic prolactin release-inhibiting factor release. Male rats were primed with estradiol and functional dopaminergic prolactin release-inhibiting factor receptors were completely blocked by pretreatment with a large dose of pimozide (3 mg/kg), a dopaminergic receptor blocking agent. The neurophysin-II stimulated prolactin release in the rats which did not have any functional dopaminergic prolactin release-inhibiting factor receptors suggesting that neurophysin-II likely initiates a chain of events which eventually stimulates prolactin-releasing factor release since the possibility of involvement of the dopaminergic prolactin release-inhibiting factor system is eliminated. Opioids are known to be one of a chain of events which transmit external stress into a stimulation of prolactin release. Naloxone, a mu-receptor antagonist, was injected 20 min before neurophysin-II administration into rats which were primed with estradiol and pretreated with pimozide (3 mg/kg), but the naloxone administration did not block the prolactin release stimulated by neurophysin-II injection. This result indicates that opioids are not one of the chain of events between initiation of stimulation by neurophysin-II and prolactin release.

Animals↗
PubMed1975

Clearance and metabolism of neurophysins by rat kidney.

The half-life in the circulation of 125I-labelled porcine neurophysins, injected intravenously into rats, was determined. The radioactivity in blood collected at intervals after injection was characterized as neurophysin by polyacrylamide gel electrophoresis. The half-life of neurophysin I was 1-5 plus or minus 0-1 (S.E.M.) min and that of neurophusin II was 1-7 plus or minus 0-1 min. The metabolic clearance rate of neurophysin I and neurophysin II was 1-9 plus or minus 0-1 and 1-3 plus or minus 0-2 ml/min/200 g respectively. Clearance from the circulation was due to both equilibration with the extravescular space and rapid specific accumulation by the kidney. The neurophysins were filtered at the glomerulus. Most of the neurophysin takken up by the kidney was incorporated into lysosomes, probably in the proximal tubule and degraded to low-molecular-weight metabolites which appeared in urine and which represented the principle mode of excretion of neurophysins.

Animals↗
PubMed1982

Photoaffinity labeling of the hormone binding site of neurophysin.

The chemical structure of the hormone binding region of the neurophysins has been investigated by photoaffinity labeling with the photolabile tripeptide, L-[methyl-3H]Met-L-Tyr-p-azido-L-Phe amide. Photolysis of the photoaffinity tripeptide in the presence of bovine neurophysin I and II and a human neurophysin II led to approximately equal extents of covalent incorporation of radioactivity into protein. Photolabeled bovine neurophysin II was fractionated into binding site derivatized protein and nonbinding site derivatized protein by affinity chromatography, with results of amino acid and radiolabel analysis of the hormone binding site blocked protein indicating that 1 mol of tripeptide was covalently incorporated/mol of protein. Tyrosine 49 was the only protein amino acid modified in the binding site photolabeling reaction as assessed by peptide mapping of the performic acid oxidized and trypsin-digested photolabeled protein using reverse phase high performance liquid chromatography. Modification of the single neurophysin tyrosine also was found by amino acid analysis of performic acid oxidized photolabeled bovine neurophysin II. The covalent bond formed in neurophysin upon photolysis was cleaved by either exhaustive acid hydrolysis or reduction-carboxymethylation without loss of the protein amino acid residues and by performic acid oxidation with loss of both protein and tripeptide tyrosine residues. These overall data indicate that tyrosine 49 is the probable site for specific covalent attachment of the photoaffinity tripeptide. Assuming that the tripeptide binding site is the high affinity hormone binding site reported for the neurophysins, this conclusion argues that tyrosine 49 is close to or within this site.

Affinity Labels↗
PubMed1987

Immunocytochemical studies of vasotocin, mesotocin, and neurophysins in the Xenopus hypothalamo-neurohypophysial system.

Mesotocinergic and vasotocinergic neurons, which constitute the principal neurons in the hypothalamo-neurohypophysial system in Xenopus, were studied by immunocytochemical techniques. Antibodies that could unequivocally distinguish mesotocin, vasotocin, and their respective neurophysins were used in these studies. A monoclonal antibody directed at rat oxytocin-associated neurophysin (PS-36) detected an antigen that was colocalized with vasotocin, whereas a monoclonal antibody to rat vasopressin-associated neurophysin (PS-45) crossreacted with an antigen in mesotocinergic cells. As vasotocin is regarded as an evolutionary precursor of vasopressin, and as mesotocin is usually associated with oxytocin, we were surprised to see this apparent eptitope switch in the associated neurophysins. One interpretation of this epitope switch is that the final exons encoding for the carboxy-terminals of the mammalian neurophysins, which contain the PS-45 and PS-36 antibody epitopes, are in reversed positions in Xenopus. Approximately 4,000 mesotocinergic and vasotocinergic neurons and their fibers were topographically mapped in the Xenopus hypothalamus. The two types of neurons were intermingled and scattered throughout a large contiguous region including but not limited to the preoptic recess. Small, medium size, and large cells contained these antigens. Immunoreactive fibers were seen in the preoptic area, the neurohypophysial tract, the median eminence, and the neural lobe of the pituitary. The neurophysin-specific monoclonal antibodies have several advantages as phenotypic markers in development; i.e., high titer, low background, and affinity for the prohormone forms as well as for the fully processed neurophysin polypeptides. Their antigens are related gene products whose expression is central to the identity of the two cell types and whose expression is differentially controlled in development. This characterization of their adult distribution provides a basis for future studies of the development of peptidergic phenotype in the central nervous system of Xenopus.

Animals↗
PubMed1975

Ontogeny of the pig hypothalamic neurosecretory system with particular reference to the distribution of neurophysin.

The immunoperoxidase cytochemical reaction was applied to the localization of neurophysin-containing elements in the fetal and adult pig hypothalamus. In the 60 day fetal pig, cells of the supraoptic nucleus (SON) were the only structues in the hypothalamus in which neurophysin was detected. However, by 87 days the cell bodies in both the SON and paraventricular nucleus (PVN) contained neurophysin-like material. The distribution of immunoreactive material in the 111 day fetal animal was similar to that found in the adult pig. In transverse section of the mature pig the SON exists in two discrete components; an antero-lateral group of cells connected by scattered cells to a smaller postero-medial group. Anteriorly, the PVN appears as a line of cells bordering the third ventricle but as we proceed posteriorly the dorsal aspect expands laterally to give a wedge-shaped group of cells. In mid-sagittal sections, the cells of the PVN are distributed over a wide area of the anterior hypothalamus in a triangular profile. The borders between the SON and PVN became more difficult to define in medial sections than in lateral sections. Continuous gradient polyacrylamide gel electrophoresis was carried out on the neural lobe extracts from fetal, newborn and adult pigs. Proteins with an electrophoretic mobility similar to that of porcine neurophysins-I, -II and -III were present in the newborn and 98 day fetal pig. It is concluded that material immunoreactive with anti-neurophysin serum is present in the hypothalamus of the 60 day fetal pig. Furthermore, at late fetal development and during the postnatal period it is tentatively suggested that the neurophysin present in the pituitaries of these animals is chemically identical with that of adult neurophysin.

Animals↗
PubMed1975

Ultrastructural immunocytochemical localization of neurophysin and vasopressin in the median eminence and posterior pituitary of the guinea pig.

With the use of tissue prepared by freeze-substitution and the unlabelled antibody enzyme technique, neurophysin and vasopressin were localized at the ultrastructural level in the pofterior pituitary and median eminence of the guinea pig. In the posterior pituitary neurophysin was found in the large neurosecretory granules (1300-1500 A) of axons, Herring bodies, and nerve terminals. In some of these axons immunoreactive neurophysin was found outside of granules in the axoplasm. By light microscopy neurophysin was found in both the zona interna and zona externa of the median eminence; this was confirmed by electron microscopy. In the zona interna as in the posterior pituitary, neurophysin was localized both inside and outside the large neurosecretory granules. In the zona externa, immunoreactive deposit was primarily located in granules with a diameter of 900-1100 A in nerve terminals abutting on the primary portal plexus. The distribution of vasopressin paralleled that of neurophysin except that the hormone was rarely extragranular. These results demonstrate for the first time that both neurophysin and vasopressin are present in granules of axons that are in contact with the hypophysial portal vasculature.

Animals↗
PubMed1984

Non-neuronal cells of rat hypothalamus in dissociated cell culture. Evidence that neurophysin modulates growth and DNA synthesis of non-neuronal cells.

The neurophysin that is biosynthesised in association with the neurohypophysial hormone vasopressin (vasopressin-neurophysin) affects the growth and DNA synthesis of rat hypothalamic non-neuronal cells in culture. Over a narrow range of concentrations vasopressin-neurophysin stimulated growth, as assessed by increase in cell numbers, about five-fold, in conditions where fetal calf serum concentration was limiting (0.2% fetal calf serum). Maximum stimulation occurred in the presence of 20 to 30 ng vasopressin-neurophysin per ml of medium. DNA synthesis was increased by a factor of three in the presence of 30 ng vasopressin-neurophysin per ml of medium. At least two populations of non-neuronal hypothalamic cells were present in the cultures, and these were both affected by vasopressin-neurophysin. This study allows the suggestion that neurophysin may be acting as a growth-regulating factor at its release site, playing a part in the interactions of neurones and glial cells in the hypothalamo-neurohypophysial system.

Animals↗
PubMed1984

Distribution of neurophysin II immunoreactive nerve fibers within the subnuclei of the nucleus of the tractus solitarius of the rat.

The location of neurophysin II immunoreactive nerve fibers and preterminal processes has been examined in various functionally distinct subnuclei of the nucleus of the tractus solitarius (nTS) using the indirect immunofluorescence method for immunocytochemistry combined with cytoarchitectonic identification. The nTS is responsible for integrating respiratory and autonomic reflex activity: the vlnTS, vnTS, ni and nI are associated with respiratory activity; the dlnTS and dnTS are important sites for the integration of baroreceptor and chemoreceptor activity; the ncom, dnTS and dlnTS integrate cardiac afferent activity and the mnTS mediates both cardiovascular and gastrointestinal effects. At levels caudal to the obex, the ncom contained the largest number of neurophysin II immunoreactive nerve fibers and the mnTS and dmnX contained moderate neurophysin II immunoreactivity. At levels rostral to the obex the region of the dorsal medulla adjacent to the mnTS and dnTS (PVR and dPSR) showed the densest immunoreactivity and the mnTS, dmnX and vPSR showed moderate immunoreactivity. At the rostral pole of the nTS, neurophysin II immunoreactive nerve terminals were seen in the dendritic regions of cells in dmnX and mnTS. This selective distribution of neurophysin II immunoreactive nerve terminals in the cardiovascular and gastrointestinal subnuclei of the nTS implicates a direct, descending, hypothalamic, oxytocin-neurophysin II containing pathway interacting with these nTS functions. These results confirm the hypothesis (Sawchenko and Swanson) that descending neurophysin II immunoreactive pathways represent an important neuronal system for the hypothalamic regulation of cardiovascular (vasomotor) and gastrointestinal nuclei in the brainstem.

Animals↗
PubMed1983

Onset of neurophysin self-association upon neurophysin/neuropeptide hormone precursor biosynthesis.

The potential of the common biosynthetic precursor of neurophysin and neuropeptide hormones to self-associate has been assessed by quantitative affinity chromatographic analysis. The precursor form, with the hormone sequence in the amino terminal region and assumed able to interact intramolecularly with the hormone binding site of the neurophysin domain of the folded precursor, exhibits an affinity for neurophysin-agarose which is intermediate between those of unliganded neurophysin and non-covalently hormone-liganded neurophysin. The results lead to a prediction that neurophysin self-association is established upon precursor synthesis and prior to limited proteolysis of the precursor to release mature neurophysin and hormone components. Such self-association could play a role in packaging of the precursor into secretory granules and in regulating subsequent precursor processing events within the granules.

Animals↗