Cortical parcellations of the macaque monkey analyzed on surface-based atlases

Surface-based atlases provide a valuable way to analyze and visualize the functional organization of cerebral cortex. Surface-based registration (SBR) is a primary method for aligning individual hemispheres to a surface-based atlas. We used landmark-constrained SBR to register many published parcellation schemes to the macaque F99 surface-based atlas. This enables objective comparison of both similarities and differences across parcellations. Cortical areas in the macaque vary in surface area by more than 2 orders of magnitude. Based on a composite parcellation derived from 3 major sources, the total number of macaque neocortical and transitional cortical areas is estimated to be about 130-140 in each hemisphere.     

Cortical connections of the inferior parietal cortical convexity of the macaque monkey

We traced the cortical connections of the 4 cytoarchitectonic fields--Opt, PG, PFG, PF--forming the cortical convexity of the macaque inferior parietal lobule (IPL). Each of these fields displayed markedly distinct sets of connections. Although Opt and PG are both targets of dorsal visual stream and temporal visual areas, PG is also target of somatosensory and auditory areas. Primary parietal and frontal connections of Opt include area PGm and eye-related areas. In contrast, major parietal and frontal connections of PG include IPL, caudal superior parietal lobule (SPL), and agranular frontal arm-related areas. PFG is target of somatosensory areas and also of the medial superior temporal area (MST) and temporal visual areas and is connected with IPL, rostral SPL, and ventral premotor arm- and face-related areas. Finally, PF is primarily connected with somatosensory areas and with parietal and frontal face- and arm-related areas. The present data challenge the bipartite subdivision of the IPL convexity into a caudal and a rostral area (7a and 7b, respectively) and provide a new anatomical frame of reference of the macaque IPL convexity that advances our present knowledge on the functional organization of this cortical sector, giving new insight into its possible role in space perception and motor control.     

Quantitative analysis of the corticocortical projections to the middle temporal area in the marmoset monkey: evolutionary and functional implications

The connections of the middle temporal area (MT) were investigated in the marmoset, one of the smallest primates. Reflecting the predictions of studies that modeled cortical allometric growth and development, we found that in adult marmosets MT is connected to a more extensive network of cortical areas than in larger primates, including consistent connections with retrosplenial, cingulate, and parahippocampal areas and more widespread connections with temporal, frontal, and parietal areas. Quantitative analyses reveal that MT receives the majority of its afferents from other motion-sensitive areas in the temporal lobe and from the occipitoparietal transition areas, each of these regions containing approximately 30% of the projecting cells. Projections from the primary visual area (V1) and the second visual area (V2) account for approximately 20% of projecting neurons, whereas "ventral stream" and higher-order association areas form quantitatively minor projections. A relationship exists between the percentage of supragranular layer neurons forming the projections from different areas and their putative hierarchical rank. However, this relationship is clearer for projections from ventral stream areas than it is for projections from dorsal stream or frontal areas. These results provide the first quantitative data on the connections of MT and extend current understanding of the relationship between cortical anatomy and function in evolution.     

Spatial organization of neurons in the frontal pole sets humans apart from great apes

Few morphological differences have been identified so far that distinguish the human brain from the brains of our closest relatives, the apes. Comparative analyses of the spatial organization of cortical neurons, including minicolumns, can aid our understanding of the functionally relevant aspects of microcircuitry. We measured horizontal spacing distance and gray-level ratio in layer III of 4 regions of human and ape cortex in all 6 living hominoid species: frontal pole (Brodmann area [BA] 10), and primary motor (BA 4), primary somatosensory (BA 3), and primary visual cortex (BA 17). Our results identified significant differences between humans and apes in the frontal pole (BA 10). Within the human brain, there were also significant differences between the frontal pole and 2 of the 3 regions studied (BA 3 and BA 17). Differences between BA 10 and BA 4 were present but did not reach significance. These findings in combination with earlier findings on BA 44 and BA 45 suggest that human brain evolution was likely characterized by an increase in the number and width of minicolumns and the space available for interconnectivity between neurons in the frontal lobe, especially the prefrontal cortex.     

An assessment of the fertilizing ability of spermatozoa in the epididymis of the marmoset monkey (Callithrix jacchus)

The fertilizing ability of spermatozoa from different regions of the epididymis of the marmoset monkey, Callithrix jacchus , was assessed by determining their rate of fusion with zonaless hamster ova in vitro. This technique tests for functional competence and was validated using epididymal spermatozoa of the hamster whose fertility have been measured previously by in vivo fertilization experiments. The results suggest that some marmoset spermatozoa first acquire the ability to fertilize in the distal caput and proximal corpus epididymidis although the majority become fertile on reaching the proximal cauda region. Acquisition of fertilizing capacity was associated with a change in the degree and character of sperm motility. However, it is considered that modifications to the sperm plasmalemma which allow capacitation and the acrosome reaction to occur are of primary importance for sperm fertility. The development of sperm fertilizing ability in the marmoset is discussed in relation to that in other primates.     

Cortical gyrification in the rhesus monkey: a test of the mechanical folding hypothesis.

A quantitative measure of the degree of cortical folding was used to test the mechanical hypothesis of cortical folding and to analyze structural properties of the rhesus monkey cortex. The rhesus monkey cortex has both its maximal degree of cortical folding and the largest ratios of supragranular laminae to the lower granular and infragranular layers in the caudal cortex, over the posterior parietal-anterior occipital regions. Low values for cortical folding and for the ratios of inner and outer cortical layers characterize frontal regions. Topographically intermediate regions are intermediate in both sets of values. Ratios of the amounts of white and gray matter have a topographic pattern that differs from those of cortical folding, suggesting that the sizes of subcortical axonal bundles are not directly associated with the degree of cortical folding. Whereas differences in mean degrees of cortical folding are correlated with brain weights among species of primates, the amount of folding is not associated with brain weight within the species.     

TGF-beta could be involved in paracrine actions in the epididymis of the marmoset monkey (Callithrix jacchus).

The transforming growth factor-beta1 (TGF-beta1) and the transforming growth factor-beta receptor type II (TGF-betaRII) were studied in the epididymis of sexually mature marmoset monkeys (Callithrix jacchus) by immunohistochemical localization of the protein and by polymerase chain reaction (PCR) analysis of the mRNA level. In order to specify reactive cell types, the morphology of all three segments (caput, corpus, and cauda epididymidis) was evaluated by light microscopy. Six different cell types could be distinguished: principal, basal, apical, and clear cells, as well as intraepithelial lymphocytes and macrophages. Using immunohistochemistry, specific staining for TGF-beta1 in the caput was found in 47% of the apical cells, whereas the TGF-betaRII was located in the apical portion of 91% of all principal cells. In the corpus epididymidis, 20% of the apical cells were immunopositive for TGF-beta, and binding of the receptor antibody occurred in 17% of the principal cells (all numbers based on counts of counterstained nuclei). All differences between percentages in the caput and corpus were significant as determined by chi-square test. PCR analysis revealed detectable levels of TGF-beta1 mRNA in the marmoset epididymis. Our results indicate for the first time that TGF-beta1 is synthesized in the marmoset epididymis, possibly in a different subpopulation of epididymal cells than the TGF-beta receptor type II. Thus, TGF-beta might be of functional relevance in the primate epididymis.     

Cortical input to the nucleus of the optic tract and dorsal terminal nucleus (NOT-DTN) in macaques: a retrograde tracing study

Using retrograde tracing methods, we investigated the cortical projection to the nucleus of the optic tract and dorsal terminal nucleus of the accessory optic system (NOT-DTN) in macaque monkeys. Tracer injections at electrophysiologically identified recording sites in the NOT-DTN resulted in retrogradely labelled neurons in layer V of various cortical areas. The strongest projection always arose from the middle temporal area (MT) and the adjoining cortex anterior to MT in the superior temporal sulcus. A less dense projection came from the middle superior temporal area (MST). In addition, retrogradely labelled cells were consistently found in areas V1 and V2 at moderate to high density. Furthermore, sparse to moderate labelling occurred in prestriate area V3. These findings were compared with the label resulting from control injections into the superior colliculus in two additional cases. Our results indicate that the cortical input to the NOT-DTN as the sensorimotor interface for the pathway subserving stabilizing eye movements during the optokinetic reflex and smooth pursuit mainly arises from the motion-sensitive areas MT and MST in the superior temporal sulcus, as well as from areas V1 and V2. Clearly the projection to the NOT-DTN does not arise from a single cortical area.     

Gunshot wound to the frontal sinus

Immediate treatment of this patient, evaluation of the wound, the use of antibiotics, and eventual reconstruction are all concerns in this complicated gunshot wound to the frontal sinus. The consultants agree that the first priority in this patient is to assess and stabilize the airway, examine the wound, and obtain a CT scan to ascertain the extent of the defect. Dr. Key feels that these wounds are contaminated and would prophylactically order a broad-spectrum cephalosporin and/or chloramphenicol. Dr. Tami would use antibiotics aimed at Staphylococcus and oral flora; Dr. Donald prefers to treat specific infections as they develop. They also agree that initial reconstruction should be conservative, aimed at covering exposed bone and minimizing local/regional flaps; however, Dr. Donald suggests using an arch bar on the intact side and eyelet wires on the injured side to address the maxillary defect. Drs. Key and Donald feel that it was a mistake to close this wound primarily and use a skin graft, because there was an inadequate soft tissue bed. Dr. Tami states that the initial management of the wound was reasonable. All agree on a basic approach to frontal sinus fractures. CT scanning is the imaging modality of choice. Nondisplaced fractures may be observed. Disruption of the posterior wall or the nasofrontal duct usually require exploration and obliteration of the sinus. Dr. Key would ablate the sinus only in cases where the anterior table is completely lost. Drs. Tami and Donald agree that cranialization should be reserved for comminuted posterior table fractures. After recognizing a CSF leak, Dr. Key would begin a broad-spectrum antibiotic.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ureteral duplication with lower pole ectopia to the epididymis

We report a unique case of a duplex ureter with ureteral ectopia. A 30-year-old man presented with a coliform infection of the epididymis and excretory urography revealed, in addition to a normal-appearing right renal collecting system, a second right ureter that arose from an inferior calix, penetrated the lower pole parenchyma and drained directly into the ipsilateral epididymis. The radiological evaluation and surgical management are discussed, and several embryological explanations for this anomaly are offered.     

Transorbital penetrating injuries to the frontal lobe

Three cases of transorbital penetrating trauma to the frontal lobe are reported. These cases are remarkable in that minimal ocular trauma was incurred and excellent vision was preserved. These cases underscore the importance of suspecting the possibility of intracranial injury when evaluating penetrating orbital trauma.     

Injury to the orbital plate of the frontal bone

Twelve cases of fracture of the orbital plate of the frontal bone are reviewed to clarify this important clinical problem and to suggest satisfactory methods of management. Common signs and symptoms include forehead laceration and deformity, and fracture of the frontal sinus. Loss of vision can occur, and in the seeing eye, diplopia can develop in several fields of gaze. Downward or upward projection of the orbital plate of the frontal bone can cause exophthalmos or enophthalmos. Cerebrospinal fluid leak, with or without meningitis, and seizures can also be part of the syndrome. Effective treatment consists of repairing or obliterating the frontal sinus, reducing the orbital root fracture, and repositioning the globe. Rib or iliac crest grafts, acrylic implants, and temporalis muscle-galea flaps are useful in correcting the deformity and restoring appropriate function. Long-term follow-up examinations are an important part of patient care.     

Cortical connections of functional zones in posterior parietal cortex and frontal cortex motor regions in new world monkeys

We examined the connections of posterior parietal cortex (PPC) with motor/premotor cortex (M1/PM) and other cortical areas. Electrical stimulation (500 ms trains) delivered to microelectrode sites evoked movements of reach, defense, and grasp, from distinct zones in M1/PM and PPC, in squirrel and owl monkeys. Tracer injections into M1/PM reach, defense, and grasp zones showed dense connections with M1/PM hand/forelimb representations. The densest inputs outside of frontal cortex were from PPC zones. M1 zones were additionally connected with somatosensory hand/forelimb representations in areas 3a, 3b, and 1 and the somatosensory areas of the upper bank of the lateral sulcus (S2/PV). Injections into PPC zones showed primarily local connections and the densest inputs outside of PPC originated from M1/PM zones. The PPC reach zone also received dense inputs from cortex caudal to PPC, which likely relayed visual information. In contrast, the PPC grasp zone was densely connected with the hand/forelimb representations of areas 3a, 3b, 1, and S2/PV. Thus, the dorsal parietal-frontal network involved in reaching was preferentially connected to visual cortex, whereas the more ventral network involved in grasping received somatosensory inputs. Additional weak interlinks between dissimilar zones (e.g., PPC reach and PPC grasp) were apparent and may coordinate actions.     

Differential contributions of dopamine and serotonin to orbitofrontal cortex function in the marmoset

We have shown previously that the inhibitory control functions of the orbitofrontal cortex (OFC) are disrupted by serotonin, but not dopamine depletions. However, both dopamine and serotonin terminals and receptors are present within the OFC and thus the aim of the present study was to determine the differential contributions of these neurotransmitters to orbitofrontal function. OFC and dopamine are involved in the process by which neutral stimuli take on reinforcing properties, by virtue of their prior association with reward, and guide behavior. Thus, we compared the performance of marmosets with dopaminergic or serotoninergic OFC depletions on a test of conditioned reinforcement. To further our understanding of serotonin in behavioral flexibility, the effect of these depletions was also compared on the extinction of a visual discrimination. Monkeys with serotonin depletions of the OFC displayed stimulus-bound responding on both tests of conditioned reinforcement and discrimination extinction suggesting that orbitofrontal serotonin plays a specific role in preventing competing, task irrelevant, salient stimuli from biasing responding. In contrast, monkeys with dopamine depletion were insensitive to conditioned reinforcers and displayed persistent responding in the absence of reward in extinction, a pattern of deficits that may reflect basic deficits in the associative processing of reward.     

Immunological characterization of hemopoietic cells in the common marmoset, rhesus monkey, and man. In search of a model for human marrow transplantation

Bone marrow, lymphoid, and peripheral blood cells from the common marmoset and rhesus monkey have been tested with a panel of heterologous and monoclonal antibodies, and their reactivity pattern has been compared with that of blood and bone marrow cells from human donors. Conventional antibodies reveal extensive cross-reactivity within the B cell, T cell, and granulocytic systems in all three species, however, some important differences have been exposed. Only the monoclonal antibodies to HLA-A,B,C and Ia-like antigens react with marmoset cells, and we have exploited this finding to show that the vast majority of colony-forming units (CFU-c) in the marmoset bone marrow (as in man) are Ia positive. The use of the common marmoset as a suitable model for human bone marrow transplantation is discussed in the light of these findings.     

Response of Cortical Bone to Antiresorptive Treatment

A total of 113 postmenopausal women (69 controls, 33 using hormone replacement therapy (HRT), and 11 using bisphosphonate) were evaluated twice over 2 years with a new noninvasive, radiogrammetry-based technique called digital X-ray radiogrammetry (DXR) and conventional bone densitometry of the spine, hip, and forearm. Longitudinal changes in bone densitometry were compared with changes captured by DXR: BMD evaluated by DXR (BMDDXR), cortical thickness of the second metacarpal (CTMC2), and porosity of cortical bone. The expected annual postmenopausal reduction in BMD in the control group was detected by BMDspine (-0.8%, P < 0.01), BMDhip (-1.6%, P < 0.001), BMDforearm (-1.5%, P < 0.001), DXR-BMD (-0.8%, P < 0.001), and CTMC2 (-1.1%, P < 0.001). In the HRT group, smaller reductions were seen in BMDDXA, but only significant at the hip (-1.0%, P < 0.01) and distal forearm (-1.0%, P < 0.02). In the bisphosphonate group, cortical porosity was significantly reduced (P < 0.025). Comparing longitudinal changes in age-matched subsamples of controls and bisphosphonate treated, BMDDXR, CTMC2, and porosity of cortical bone all differed significantly (P < 0.01, P < 0.05, P < 0.05, respectively), whereas the BMDDXA measurements did not. In conclusion, DXR provides a densitometry equivalent measurement of the distal forearm and hand and seems to offer new information on the porosity of cortical bone. This may prove useful in the evaluation of bone loss and offer new insight into the effects of different antiresorptive treatment regimens used in the prevention of osteoporosis.     

Squamous cell carcinoma of the frontal sinus caused osteomyelitis of the frontal bone

A case of the squamous cell carcinoma of the frontal sinus complicated with osteomyelitis of the frontal bone was reported. A 47-year-old male was admitted to Asahikawa Medical College Hospital because of a bulging of forehead and remittent fever of a six-month history and general convulsive seizures on the day before admission. On physical examination, a bulging of forehead with redness, tenderness and fluctuation was noted. Sense of smell diminished bilaterally. Oto-laryngological examination disclosed paranasal sinusitis. Skull X-P and CT scan suggested osteomyelitis of the frontal bone secondary to frontal sinusitis. However, a frontal sinus tumor with osteomyelitis was also possible. Operation was performed and a granulomatous mass attached to the dura with thick epidural abscess was noted. The mass and affected bone edge were removed. Pathological examination of the specimens disclosed findings of squamous cell carcinoma and osteomyelitis. Recurrence of the tumor rapidly occurred and reoperation was performed a month after the first operation. Postoperative irradiation and chemotherapy with pepleomycin were done but failed to control the growth and recurrence occurred immediately. The tumor penetrated the skin of the forehead and the patient died of cachexy 7 months after the first surgery. Osteomyelitis usually occurred in the metaphysis of long tubular bone and rarely in short bone or flat bone such as a skull. This is attributed to the difference of distribution of the bone marrow vessels. Embolization and subsequent growth of bacteria in the blood flow is less liable to occur in short bone and flat bone.(ABSTRACT TRUNCATED AT 250 WORDS)