Anti-neurofilament Protein Research Articles

Fluoxetine pretreatment enhances neurogenic, angiogenic and immunomodulatory effects of MSCs on experimentally induced diabetic neuropathy.

Being one of the most debilitating complications among diabetic patients, diabetic polyneuropathy (DPN) is a paramount point of continuous research. Stem cell therapies have shown promising results. However, limited cell survival and paracrine activities hinder its transfer from bench to bedside. We designed this study to evaluate fluoxetine-pretreatment technique of mesenchymal stem cells (MSCs) as an approach to enhance their paracrine and immunomodulatory properties in DPN. Effects of fluoxetine treatment of MSCs were tested in vitro. Forty-two adult Wistar male albino rats were utilized, further subdivided into control, diabetic, MSC-treated and fluoxetine-pretreated MSC groups. Sciatic nerve sections were prepared for light and electron microscope examination and immunohistochemical detection of neurofilament (NF) protein. Also, we assessed in vitro survival and paracrine properties of fluoxetine-pretreated MSCs. Real time PCR of BDNF, VEGF, IL-1β, and IL-10 expression in tissue homogenate was performed. Our results showed restoration of normal neuronal histomorphology and ultrastructure, moreover, immunohistochemical expression of anti-neurofilament protein was significantly elevated in MSC-treated groups compared to the diabetic one. Fluoxetine enhanced the MSC survival and their paracrine properties of MSCs in vitro. Furthermore, the fluoxetine-pretreated MSC group revealed a significant elevation of mRNA expression of BDNF (neurotrophic factor) and VEGF (angiogenic factor), denoting ameliorated MSC paracrine properties. Similarly, improved immunomodulatory functions were evident by a significant reduction of interleukin-1β mRNA expression (pro-inflammatory) and a reciprocal significant increase of interleukin-10 (anti-inflammatory). We concluded that fluoxetine-pretreatment of MSCs boosts their survival, paracrine, and immunomodulatory traits and directly influenced neuronal histomorphology. Hence, it presents a promising intervention of diabetic polyneuropathy. Graphical Abstract.

Using a Whole-mount Immunohistochemical Method to Study the Innervation of the Biliary Tract in Suncus murinus.

This work describes the whole-mount immunohistochemistry staining method in detail, using neurofilament protein antibody to label the innervation of the biliary tract in Suncus murinus (S. murinus). First, the specimen was dissected from S. murinus and fixed in 4% paraformaldehyde (PFA). Second, an enzymatic treatment and potential endogenous peroxidase inactivation were performed. The specimen was then exposed to the primary antibody, anti-neurofilament protein antibody, for 3-6 days. It was then incubated with the secondary antibody conjugated with horseradish peroxidase. The color reaction was revealed by reacting the specimen with a 3,3'-diaminobenzidine (DAB) substrate. This method can be applied to analyze the innervation of all visceral organs. Furthermore, this protocol can also be adapted to test other neuronal antibodies, but optimization of the antibodies should be done first. This method was originally introduced by Kuratani and Tanaka1,2,3.

Isolation of Low Abundance Proteins and Cells Using Buoyant Glass Microbubble Chromatography

Conventional protein affinity chromatography relies on highly porous resins that have large surface areas. These properties are ideal for fast flow separation of proteins from biological samples with maximum yields, but these properties can also lead to increased nonspecific protein binding. In certain applications where the purity of an isolated protein is more important than the yield, using a glass solid phase could be advantageous as glass is nonporous and hydrophilic and has a low surface area and low nonspecific protein binding. As a proof of principle, we used protein A-conjugated hollow glass microbubbles to isolate fluorescently labeled neurofilament heavy chain spiked into serum and compared them to protein A Sepharose and protein A magnetic beads (Dynabeads) using an anti-neurofilament protein antibody. As expected, a greater volume of glass bubbles was required to match the binding capacity of the magnetic beads and Sepharose resins. On the other hand, nonspecific protein binding to glass bubbles was greatly reduced compared to the other resins. Additionally, since the glass bubbles are buoyant and transparent, they are well suited for isolating cells from biological samples and staining themin situ.

Reconstruction of the Abdominal Vagus Nerve Using Sural Nerve Grafts in Canine Models

BackgroundRecently, vagus nerve preservation or reconstruction of vagus has received increasing attention. The present study aimed to investigate the feasibility of reconstructing the severed vagal trunk using an autologous sural nerve graft.MethodsTen adult Beagle dogs were randomly assigned to two groups of five, the nerve grafting group (TG) and the vagal resection group (VG). The gastric secretion and emptying functions in both groups were assessed using Hollander insulin and acetaminophen tests before surgery and three months after surgery. All dogs underwent laparotomy under general anesthesia. In TG group, latency and conduction velocity of the action potential in a vagal trunk were measured, and then nerves of 4 cm long were cut from the abdominal anterior and posterior vagal trunks. Two segments of autologous sural nerve were collected for performing end-to-end anastomoses with the cut ends of vagal trunk (8–0 nylon suture, 3 sutures for each anastomosis). Dogs in VG group only underwent partial resections of the anterior and posterior vagal trunks. Laparotomy was performed in dogs of TG group, and latency and conduction velocity of the action potential in their vagal trunks were measured. The grafted nerve segment was removed, and stained with anti-neurofilament protein and toluidine blue.ResultsLatency of the action potential in the vagal trunk was longer after surgery than before surgery in TG group, while the conduction velocity was lower after surgery. The gastric secretion and emptying functions were weaker after surgery in dogs of both groups, but in TG group they were significantly better than in VG group. Anti-neurofilament protein staining and toluidine blue staining showed there were nerve fibers crossing the anastomosis of the vagus and sural nerves in dogs of TG group.ConclusionReconstruction of the vagus nerve using the sural nerve is technically feasible.

Histological analysis of the rectus capitis posterior major's myodural bridge

Background contextIn recent literature, a soft-tissue communication between the rectus capitis posterior major (RCPma) muscle and the cervical dura mater has been identified. To the best of our knowledge, this communication has yet to be validated from a histological perspective nor has it been examined for neural tissue. PurposeThe purpose of this study was to examine the composition and true continuity of the communication between the RCPma and the dura mater at a microscopic level. The communication was also inspected for the presence of proprioceptive neurons. Study designAn anatomical and histological analysis of a novel structure in the atlantoaxial interspace. MethodsGross dissection was performed on 11 cadavers to remove the RCPma, the soft-tissue communication, and a section of posterior cervical dura mater as one continuous unit. Paraffin embedding and sectioning followed by hematoxylin and eosin staining was conducted to validate the connection. Staining with antineurofilament protein fluorescent antibodies was performed to identify proprioceptive neural tissue on one specimen, and all findings were recorded via photographic documentation. ResultsHistological investigation revealed a tendinous matrix inserting into both the RCPma and the posterior aspect of the cervical dura mater in all 11 specimens. In the one specimen examined for neural tissue, antineurofilament protein fluorescence revealed proprioceptive neurons within the communication. Immunoperoxidase staining demonstrated the insertion of these neurons into both the dura mater and the belly of the RCPma. ConclusionsThe existence of a true connection between the RCPma and the cervical dura mater provides new insight in understanding the complex anatomy of the atlantoaxial interspace. The presence of a neural component within this connection suggests that it may serve another function aside from simply anchoring this muscle to the dura mater. Such a connection may be involved in monitoring dural tension and may also play a role in certain cervicogenic pathologies. This study also supports previous reports that no true membrane joins the posterior arch of the atlas to the laminae of the axis and contradicts the conventional belief that the ligamentum flavum joins these two structures.

Density of small diameter sensory nerve fibres in endometrium: a semi-invasive diagnostic test for minimal to mild endometriosis

The aim of our study was to test the hypothesis that multiple-sensory small-diameter nerve fibres are present in a higher density in endometrium from patients with endometriosis when compared with women with a normal pelvis, enabling the development of a semi-invasive diagnostic test for minimal-mild endometriosis. Secretory phase endometrium samples (n = 40), obtained from women with laparoscopically/histologically confirmed minimal-mild endometriosis (n = 20) and from women with a normal pelvis (n = 20) were selected from the biobank at the Leuven University Fertility Centre. Immunohistochemistry was performed to localize neural markers for sensory C, Adelta, adrenergic and cholinergic nerve fibres in the functional layer of the endometrium. Sections were immunostained with anti-human protein gene product 9.5 (PGP9.5), anti-neurofilament protein, anti-substance P (SP), anti-vasoactive intestinal peptide (VIP), anti-neuropeptide Y and anti-calcitonine gene-related polypeptide. Statistical analysis was done using the Mann-Whitney U-test, receiver operator characteristic analysis, stepwise logistic regression and least-squares support vector machines. The density of small nerve fibres was approximately 14 times higher in endometrium from patients with minimal-mild endometriosis (1.96 +/- 2.73) when compared with women with a normal pelvis (0.14 +/- 0.46, P < 0.0001). The combined analysis of neural markers PGP9.5, VIP and SP could predict the presence of minimal-mild endometriosis with 95% sensitivity, 100% specificity and 97.5% accuracy. To confirm our findings, prospective studies are required.

Endometrial nerve fibers in women with endometriosis, adenomyosis, and uterine fibroids

To determine whether nerve fibers in the functional layer endometrium are caused by an endometriosis itself or a common symptom of pain, endometrial tissues from 30 women with endometriosis, 40 women with adenomyosis, 41 women with uterine fibroids, and 47 endometriosis women with adenomyosis were stained immunohistochemically using the highly specific polyclonal rabbit antiprotein gene product 9.5 (PGP9.5) and monoclonal mouse antineurofilament protein. We demonstrated PGP9.5-immunoactive nerve fibers in the functional layer of endometrium in women with pain symptoms, but not in women without pain symptoms, whether the women had endometriosis, adenomyosis, uterine fibroids, or endometriosis with adenomyosis, suggesting a role of PGP9.5-immunoactive nerve fibers in the functional layer of the endometrium playing in pain generation in these disorders.

Distribution of nerve fibers in endometrium and its clinical significance in adenomyosis

To investigate nerve fibers distribution in endometrium of adenomyosis and their relationship with dysmenorrhea. Endometrial tissue was sampled from 74 hysterectomy specimens including 32 cases with adenomyosis and 42 cases with uterine fibroids. Two-step Envision immunohistochemical staining was used to detect distribution of nerve fibers in endometrium. Highly specific polyclonal rabbit anti-protein gene product 9.5 (PGP9.5) and monoclonal mouse anti-neurofilament protein (NF) were used to demonstrate both myelinated and unmyelinated nerve fibers in endometrium in women with adenomyosis and uterine fibroids. The positive rate of PGP9.5 immunoreactive nerve fibers in the functional layer of endometrium of pain patients were with 64% (14/22) in adenomyosis and 67% (10/15) in uterine fibroids. And their density were 0.6 (0 - 9.4)/mm(2) and 0.6 (0 - 6.0)/mm(2) without reaching statistical difference (P > 0.05). No expression of NF could be detected in the functional layer of endometrium of adenomyosis and uterine fibroids. There were no PGP9.5 immunoreactive nerve fibers in the functional layer of endometrium in non-pain women with adenomyosis and uterine fibroids. Moreover, No NF immunoreactive nerve fibers in the functional layer of endometrium were shown in non-pain patients with adenomyosis and uterine fibroids. PGP9.5 immunoreactive nerve fibers and the nerve density in the basal layer of endometrium were 64% (14/22), 1.1 (0 - 12.0)/mm(2) in pain adenomyosis and 50% (5/10), 0.6 (0 - 3.0)/mm(2) in non-pain adenomyosis. NF immunoreactive nerve fibers and the density in the basal layer of endometrium were 23% (5/22), (0 - 0.6)/mm(2) in pain adenomyosis and 20% (2/10), (0 - 1.0)/mm(2) in non-pain adenomyosis. PGP9.5 immunoreactive nerve fibers and the nerve density in the basal layer of endometrium were 80% (12/15) and 1.6 (0 - 10.0)/mm(2) in pain fibroids and 44% (12/27), 0 (0 - 5.0)/mm(2) in non-pain fibroids. NF immunoreactive nerve fibers and the nerve density in the basal layer of endometrium were 40% (6/15), 0 (0 - 0.4)/mm(2) in pain fibroids and 15% (4/27), 0 (0 - 1.0)/mm(2) in non-pain fibroids. There was no statistical different PGP9.5 and NF immunoreactive nerve fibers distribution in basal layer of endometrium between pain adenomyosis and pain fibroids or between non-pain adenomyosis and non-pain fibroids (all P > 0.05). However, PGP9.5 immunoreactive nerve fibers density in basal layer of endometrium was higher in pain adenomyosis and fibroids when compared with non-pain adenomyosis and fibroids (P < 0.05). PGP9.5 immunoreactive nerve fibers might confer the occurrence of pelvic pain, however, NF immunoreactive nerve fibers may not involved in the pathogenesis of pain.

Innervation of endometrium and myometrium in women with painful adenomyosis and uterine fibroids

To determine whether nerve fibers can be detected in the endometrium and myometrium in women with painful uterine fibroids and adenomyosis. A retrospective immunohistochemical study. An academic training hospital. Thirty-seven women with uterine fibroids and 29 women with adenomyosis. Histologic sections of contiguous endometrial and myometrial tissues were stained immunohistochemically using the highly specific polyclonal rabbit antiprotein gene product 9.5 (PGP9.5) and monoclonal mouse antineurofilament protein (NF). Results were determined through immunohistochemical staining using PGP9.5 and NF. We detected PGP9.5-immunoactive nerve fibers in the functional layer of the endometrium in women with pain but not in women without pain. PGP9.5-immunoactive nerve fiber density in the basal layer of the endometrium or myometrium significantly increased in women with pain, however, PGP9.5-immunoactive nerve fiber density had no statistical differences between women with adenomyosis and uterine fibroids. We identified NF-immunoactive nerve fibers in the basal layer of the endometrium and myometrium in women with adenomyosis and uterine fibroids, but found no significant differences. These results suggest that PGP9.5-immunoactive nerve fibers appearing in the endometrium and myometrium of women with painful adenomyosis and uterine fibroids may play a role in pain generation in these two disorders.

Involuntary, Electrically Excitable Nerve Transfer for Denervation: Results From an Animal Model

The purpose of this study was to evaluate the efficacy of "paralyzed" nerve transfer (ie, transfer of an involuntary, nondegenerated, electrically excitable nerve onto an involuntary, degenerated, non-electrically excitable nerve) and functional electrical stimulation for reinnervation. We hypothesized that lower motor neuron cell body continuity with the motor cortex, via intact upper motor neurons, is not necessary for reinnervation of the extremities. Fischer 344 rats had lower thoracic spinal cord injury (SCI) followed by unilateral tibial nerve transection and delayed peroneal ("paralyzed") to tibial nerve transfer (group A) or primary neurorrhaphy (group B). Control groups had SCI and a unilateral hindlimb incision and nerve exposure only (group C) or a unilateral hindlimb disection and transection of both the tibial and peroneal nerves (group D). Three months after surgery, the proximal peroneal (group A) or proximal tibial (groups B, C, and D) nerves were electrically stimulated in vivo, and gastrocnemius force production was measured on both the operative and nonoperative hindlimbs. In addition, the distal tibial nerves from both the experimental and control-side hindlimbs were sectioned and stained with anti-neurofilament protein to determine total axon counts. Mean gastrocnemius force return and mean axonal regeneration was 47% and 51%, respectively, for group A animals (n = 9), 68% and 73% for group B animals (n = 4), 97% and 99% for group C animals (n = 4), and 0 and 2% for group D animals (n = 4). A 1-way analysis of variance for independent samples yielded significant differences between groups A, B, and C for gastrocnemius force return and between all groups for axonal regeneration. Paralyzed nerve transfer produces a mean of approximately 50% return of gastrocnemius force and axonal regeneration. Paralyzed nerve transfer combined with functional electrical stimulation is a viable method for reanimating denervated motor units in the setting of SCI.

Dental Pulp Changes Observed in a Patient on Long-term Corticosteroids

We encountered a patient on long-term oral corticosteroids for systemic lupus erythematosus, who did not complain of pain during caries treatment. Since the patient had no subjective sense of dental pain, all her remaining teeth became stumps, and total tooth extraction was conducted 25 years after presentation. We examined her premolar stumps histopathologically and obtained the following findings: 1. the dental pulp was narrowed in nearly all samples; 2. odontoblasts were not observable; 3. regions with dentinal tubules forming lamellae and regions with fibrotic dentinal tubules were observed. 4. fibrosis of the entire dentin was observed in some regions. 5. nerve fibers stained by anti-neurofilament protein antibody were observed in the dental pulp cavity, but the nerve fibers appeared degenerate and no nerve fiber endings were observed.

High density of small nerve fibres in the functional layer of the endometrium in women with endometriosis

Endometriosis is a common gynaecological disease and is frequently associated with recurrent and serious pelvic pain such as dysmenorrhoea and dyspareunia, but the mechanisms by which these symptoms are generated are not well understood. Histological sections of endometrial tissue were prepared from endometrial curettings and hysterectomies performed on women with endometriosis (n=25 and n=10, respectively) and without endometriosis (n=47 and n=35, respectively). These were stained immunohistochemically for the highly specific polyclonal rabbit anti-protein gene product 9.5 (PGP9.5) and monoclonal mouse anti-neurofilament protein (NF) to demonstrate both myelinated and unmyelinated nerve fibres. Small nerve fibres were identified throughout the basal and functional layers of the endometrium in all endometriosis patients, but were not seen in the functional layer of the endometrium in any of the women without endometriosis (P<0.001). NF-immunoreactive nerve fibres were present in the basal layer in all endometriosis patients but not in non-endometriosis patients, with one exception (P<0.001). Small nerve fibres detected in the functional layer in all women with endometriosis may have important implications for understanding the generation of pain in these patients. The presence of nerve fibres in an endometrial biopsy may be a novel surrogate marker of clinical endometriosis.

Surgical Anatomy of the Innervation of the Major Duodenal Papilla in Human and Suncus Murinus, From the Perspective of Preserving Innervation in Organ-saving Procedures

Few studies have focused on the detailed surgical anatomy of the innervation of the major duodenal papillary region, especially in relation to duodenum-preserving pancreatic head resection (DPPHR) and its modified procedures, which is crucial to preserving the innervation of the papillary region. The aim of this study is to clarify the neural distribution of the major duodenal papilla in humans. The pancreas, duodenum, and surrounding structures were dissected in 10 cadavers and immersed in a 0.001% solution of alizarin red S in ethanol to stain the peripheral nerves. The details of the innervation in the above areas were confirmed using a binocular microscope. Similarly, the distribution in 10 Suncus murinus was examined by whole mount immunohistochemistry method with antineurofilament protein antibody. The innervation of the papillary region in humans involved 2 systems. One arose from the celiac plexus, which through the anterior hepatic plexus running along the arcades of the superior pancreaticoduodenal arteries and through the posterior hepatic plexus running along or accompanying the common bile duct (CBD) or Wirsung's duct, innervated the papillary region. The other arose from the superior mesenteric plexus wound around the arcades of the inferior pancreaticoduodenal arteries innervating the papillary region. The results in S. murinus supported those in humans. We emphasize the importance of the nervus-preserving of the major duodenal papilla and CBD by a suitable pancreatic head remnant, preserving the pancreaticoduodenal arterial arcades and avoiding kocherization of the CBD in DPPHR and its modified procedures.

Benign Epithelioid Peripheral Nerve Sheath Tumors of the Soft Tissues

Benign epithelioid peripheral nerve sheath tumors (BEPNSTs) have not been fully characterized, and their relationship to conventional schwannoma and neurofibroma has not been satisfactorily established. Herein, we detail the clinicopathologic features of 33 examples of BEPNST. The study included 22 females and 11 males ranging in age from 2 to 68 years (median, 31.5 years). Only one patient probably has neurofibromatosis type 1. The tumors were predominantly dermal/subcutaneous in location (85%) and involved the lower limb (n=15), upper limb (n=11), trunk (n=4), and head/neck (n=3). The lesions ranged in size from 0.3 to 6.8 cm (median, 1.1 cm). Microscopically, the tumors were generally well-circumscribed, uninodular, or multinodular masses. Twenty-six lesions were encapsulated. Tumors consisted of trabeculae, loosely arranged nodules, and cohesive nests of epithelioid tumor cells immersed in collagenous, myxohyaline, or chiefly myxoid stroma. A bland spindled cell component comprising 5% to 40% of the tumor was noted in 15 cases. Mitotic activity ranged from 0 to 6 mitoses/50 high power fields (mean, 1.5 mitoses/50 high power fields) with no abnormal division figures identified. Five lesions were considered atypical based on presence of focal nuclear/nucleolar enlargement and hyperchromasia. Immunohistochemical reactivity for Schwann cell-related markers in tumor cells included S-100 protein (20 of 20 cases), collagen type IV (10 of 10), laminin (8 of 8), nerve growth factor receptor, p75(7 of 8), CD57 (6 of 9), and glial fibrillary acidic protein (8 of 15). CD34-positive fibroblast-like cells were identified in all 12 neoplasms tested. Anti-epithelial membrane antigen highlighted perineurial cells in 9 of the 11 encapsulated tumors. Anti-neurofilament protein did not identify intralesional neuraxons in the 10 tumors evaluated. Eighteen tumors were subtyped as epithelioid neurofibromas. The remaining 15 cases showed some histologic features suggestive of schwannoma, but their uniform cellularity, absence of nuclear palisading, and presence of a significant CD34-positive spindled cell population in 5 cases led to their classification as "BEPNST of indeterminate histogenesis." Evaluation for loss of heterozygosity in 2 cases demonstrated deletion of genetic material on chromosome 22q and 17q involving NF2 and NF1 loci. However, sequencing of NF2 coding sequences revealed no mutations. Follow-up for 18 patients (median interval, 13.5 years), including 4 patients with tumors exhibiting cytologic atypia, revealed a nondestructive recurrence or persistent disease in 3 patients whose tumors lacked atypia, but no evidence of metastatic spread or tumor-related death. BEPNSTs are usually small neoplasms located in superficial soft tissue and have an excellent prognosis after complete local excision. Accurate subclassification of some of these lesions is difficult based on currently available techniques.

Intracytoplasmic inclusion bodies of the substantia nigra in myotonic dystrophy: Immunohistochemical observations

We recently reported a significantly higher incidence of intracytoplasmic inclusion bodies (IIBs) of the substantia nigra in patients with myotonic dystrophy (MyD) than in age-matched controls. The changes are, per se, not specific, since a small percentage of disease and normal controls also showed similar inclusions. To elucidate the pathological significance of the inclusion in MyD, we studied immunohistochemical characteristics of IIBs of the substantia nigra in eight patients with MyD. Many IIBs showed moderately intense immunoreactivity for ubiquitin, microtubule-associated protein (MAP) 1 and MAP 2. However, the IIBs did not react with any of the following: anti-neurofilament protein antibodies (Abs) (68, 160 and 200 kDa), anti-neuron-specific enolase antibody (Ab), anti-tau Ab, anti-tubulin Abs (alpha and beta), anti-paired helical filament Ab, anti-actin Ab, anti-phosphorylated epitope of neurofilaments Ab, anti-synaptophysin Ab, anti-myelin basic protein Ab, anti-actin Ab and anti-glial fibrillary acidic protein Ab. Our results suggest that IIBs of the substantia nigra in MyD are related to an alteration of neuronal cytoskeleton metabolism affecting microtubular proteins in conjunction with activation of ubiquitin proteolytic systems.

Immunohistochemical study of intracytoplasmic inclusion bodies of the thalamus in myotonic dystrophy

Intracytoplasmic inclusion bodies of the thalamus in eight patients with myotonic dystrophy (MyD) were studied immunohistochemically. The intracytoplasmic inclusion bodies of the thalamus (thalamic inclusions, TIs) were strongly immunostained with anti-ubiquitin antibody (Ab) and some of them were mildly stained with anti-microtubule associated protein 1 (MAP 1) and anti-MAP 2 antibodies. However, TIs did not react with any of the following: anti-neurofilament protein Ab, anti-tau Ab, anti-paired helical filament Ab, anti-tubulin Abs (alpha and beta), anti-neuron-specific enolase Ab, anti-glial fibrillary acidic protein Ab, anti-synaptophysin Ab, anti-myelin basic protein Ab, anti-actin Ab and anti-phosphorylated epitope of neurofilaments Ab. Thus, our study demonstrates the unique immunohistochemistry of TIs in MyD which differentiates them from other intracytoplasmic inclusions in various neurodegenerative disorders.

Cranial nerves and brain fiber systems of the medaka fry as observed by a whole-mount staining method

The cranial nerves and the brain fiber systems of the medaka ( Oryzias latipes) fry are revealed by a whole-mount staining method. Newly hatched fry of an albino strain of the medaka were fixed, partially digested with trypsin, treated in 1% Triton X-100, and finally immunohistochemically stained using anti-neurofilament protein (70K+160K+210K) antibodies. Since both head skin and eyes were colorless in the albino fish, the three-dimensional distribution of nerve fibers in the brain could be readily observed in whole specimens without interference of pigment cells. All cranial nerves and main fiber systems in the adult fish were differentiated in the fry brain. Using this method, the distribution of nerves to the ocular muscles and the periorbital pit organs was shown.

Intraventricular infusions of anti-neural cell adhesion molecules in a discrete posttraining period impair consolidation of a passive avoidance response in the rat.

Intraventricular infusions of anti-neural cell adhesion molecule (anti-NCAM) are demonstrated to inhibit consolidation of a passive avoidance response when administered in the 6-8 h posttraining period. Anti-NCAM was ineffective when administered during training or at any other time up to 10 h thereafter, and no amnesic effects were observed with absorbed anti-NCAM or anti-neurofilament protein. Amnesia was observed only at the 48-h recall time, and this could not be attributed to poor antibody penetration or a prolonged residence time, as studies with 125I-labelled anti-NCAM in trained animals demonstrated a rapid accumulation into all brain regions, and this was marked in the olfactory bulb and hippocampus, areas showing an inherent and paradigm-specific increase in NCAM sialylation state, respectively. The lack of an amnesic action at the 24-h recall time is attributed to anti-NCAM-impaired synapse structuring becoming apparent following the paradigm-specific increases in NCAM sialylation state.

Synthetic amyloid β-protein fails to produce specific neurotoxicity in monkey cerebral cortex

Because progressive amyloid β-protein (AβP) deposition and surrounding neuritic dystrophy occur spontaneously in primates, we evaluated the in vivo effects of synthetic AβP in monkey cortex. Experimental and control AβP were stereotactically injected into multiple neocortical sites of adult rhesus monkeys in a vehicle of either artificial cerebrospinal fluid or acetonitrile. After 2 weeks or 3 months, injection sites were identified and characterized histologically and immunocytochemically. AβP antibodies specifically detected the injected AβP1–40 peptide. Serial sections stained with silver and antineurofilament protein demonstrated comparable degrees of degenerating neurons, dystrophic neurites, and axonal spheroids associated with both experimental and control peptide injections. Alz 50 staining was sparse or absent in all sites. We conclude that specific cellular changes closely resembling AD pathology were not detected in these experiments, and that control and experimental AβP peptides produced indistinguishable effects. Methodological concerns regarding the in vivo modeling of AβP bioactivity are discussed.

Simultaneous detection of ferritin and HIV-1 in reactive microglia.

Using ferritin as a marker of reactive microglia, we demonstrated a close association between proliferation of reactive microglia and expression of human immunodeficiency virus type 1 (HIV-1) in brain tissue from autopsied cases of acquired immunodeficiency syndrome (AIDS). An increased number of ferritin-positive reactive microglia was observed in formalin-fixed paraffin-embedded brain sections from all 13 AIDS cases examined. Similar findings were observed in brain tissue from other neurological diseases (subacute sclerosing panencephalitis, herpes simplex encephalitis and multiple sclerosis). Multinucleated giant cells were found in 7 of the AIDS cases which were also intensely labeled for ferritin. Dual-label immunohistochemistry using anti-ferritin and cell-specific markers showed that ferritin-positive cells were distinct from astrocytes, neurons and endothelia using anti-glial fibrillary acidic protein (anti-GFAP), anti-neurofilament protein and Ulex europaeus agglutinin 1, respectively. In 5 AIDS brains, only ferritin-positive cells were shown to contain HIV-1 gp41 antigen using dual-label immunohistochemistry. In addition, HIV-1 RNA was localized in ferritin-positive reactive microglia but not in GFAP-positive astrocytes using immunohistochemistry combined with in situ hybridization. Ferritin-positive reactive microglia and multinucleated giant cells were co-labeled with the microglial marker, Ricinus communis agglutinin 1 (RCA-1). However, RCA-1 also extensively stained resting microglia only a few of which were co-labeled for ferritin. The density of ferritin-positive cells was correlated with the presence of HIV-1 RNA-positive cells in AIDS brain. Thus, ferritin immunoreactivity can be used as an activation marker of microglia in archival paraffin sections and reflects the extent of inflammation in HIV-1-infected brain.