Putative Neural Network Within an Olfactory Sensory Unit for Nestmate and Non-nestmate Discrimination in the Japanese Carpenter Ant: The Ultra-structures and Mathematical Simulation

Ants are known to use a colony-specific blend of cuticular hydrocarbons (CHCs) as a pheromone to discriminate between nestmates and non-nestmates and the CHCs were sensed in the basiconic type of antennal sensilla (S. basiconica). To investigate the functional design of this type of antennal sensilla, we observed the ultra-structures at 2D and 3D in the Japanese carpenter ant, Camponotus japonicus, using a serial block-face scanning electron microscope (SBF-SEM), and conventional and high-voltage transmission electron microscopes. Based on the serial images of 352 cross sections of SBF-SEM, we reconstructed a 3D model of the sensillum revealing that each S. basiconica houses > 100 unbranched dendritic processes, which extend from the same number of olfactory receptor neurons (ORNs). The dendritic processes had characteristic beaded-structures and formed a twisted bundle within the sensillum. At the “beads,” the cell membranes of the processes were closely adjacent in the interdigitated profiles, suggesting functional interactions via gap junctions (GJs). Immunohistochemistry with anti-innexin (invertebrate GJ protein) antisera revealed positive labeling in the antennae of C. japonicus. Innexin 3, one of the five antennal innexin subtypes, was detected as a dotted signal within the S. basiconica as a sensory organ for nestmate recognition. These morphological results suggest that ORNs form an electrical network via GJs between dendritic processes. We were unable to functionally certify the electric connections in an olfactory sensory unit comprising such multiple ORNs; however, with the aid of simulation of a mathematical model, we examined the putative function of this novel chemosensory information network, which possibly contributes to the distinct discrimination of colony-specific blends of CHCs or other odor detection

Effects of whole spine alignment patterns on neck responses in rear end impact

Objective: The aim of this study was to investigate the whole spine alignment in automotive seated postures for both genders and effects of the spinal alignment patterns on cervical vertebral motion in rear impact using a human Finite Element (FE) model. Methods: Image data of 8 female and 7 male subjects in a seated posture acquired by an upright open MRI system were utilized. Spinal alignment was determined from the centers of the vertebrae and average spinal alignment patterns for both genders were estimated by Multi Dimensional Scaling (MDS). An occupant FE model of female average size (162 cm, 62 kg) (the AF 50 size model) was developed by scaling THUMS AF 05. The average spinal alignment pattern for females was implemented in the model, and model validation was made with respect to female volunteer sled test data from rear end impacts. Thereafter, the average spinal alignment pattern for males and representative spinal alignments for all subjects were implemented in the validated female model, and additional FE simulations of the sled test were conducted to investigate effects of spinal alignment patterns on cervical vertebral motion. Results: The estimated average spinal alignment pattern was slight kyphotic, or almost straight cervical and less-kyphotic thoracic spine for the females, and lordotic cervical and more pronounced kyphotic thoracic spine for the males. The AF 50 size model with the female average spinal alignment exhibited spine straightening from upper thoracic vertebra level and showed larger intervertebral angular displacements in the cervical spine than the one with the male average spinal alignment. Conclusions: The cervical spine alignment is continuous with the thoracic spine, and a trend of the relationship between cervical spine and thoracic spinal alignment was shown in this study. Simulation results suggested that variations in thoracic spinal alignment had a potential impact on cervical spine motion as well as cervical spinal alignment in rear end impact condition

Analysis of the Alignment of Whole Spine in Automotive Seated and Supine Postures Using an Upright Open MRI System

The purpose of this study is to provide the alignment of whole spine in an automotive seated posture by analyzing image data acquired with an upright open MRI system. Five female and three male asymptomatic subjects were scanned in seated and supine postures, and midsagittal images were analyzed in the location of the center of vertebral body and the vertebral angle relative to lower adjacent vertebra from C2 to sacrum. Results showed that 1) females were more likely to have non-lordosis than males, 2) lumbar lordosis was larger for females than males, and sacrum slope was greater for males than females, 3) thoracic kyphosis and T1 slope were greater for the cervical lordotic type than kyphotic type in seated posture

Analysis of the Alignment of Whole Spine in Automotive Seated and Supine Postures Using an Upright Open MRI System

The purpose of this study is to provide the alignment of whole spine in an automotive seated posture by analyzing image data acquired with an upright open MRI system. Five female and three male asymptomatic subjects were scanned in seated and supine postures, and midsagittal images were analyzed in the location of the center of vertebral body and the vertebral angle relative to lower adjacent vertebra from C2 to sacrum. Results showed that 1) females were more likely to have non-lordosis than males, 2) lumbar lordosis was larger for females than males, and sacrum slope was greater for males than females, 3) thoracic kyphosis and T1 slope were greater for the cervical lordotic type than kyphotic type in seated posture

Analysis of the Alignment of Whole Spine in Automotive Seated and Supine Postures Using an Upright Open MRI System

The purpose of this study is to provide the alignment of whole spine in an automotive seated posture by analyzing image data acquired with an upright open MRI system. Five female and three male asymptomatic subjects were scanned in seated and supine postures, and midsagittal images were analyzed in the location of the center of vertebral body and the vertebral angle relative to lower adjacent vertebra from C2 to sacrum. Results showed that 1) females were more likely to have non-lordosis than males, 2) lumbar lordosis was larger for females than males, and sacrum slope was greater for males than females, 3) thoracic kyphosis and T1 slope were greater for the cervical lordotic type than kyphotic type in seated posture

Analysis of the Alignment of Whole Spine in Automotive Seated and Supine Postures Using an Upright Open MRI System

The purpose of this study is to provide the alignment of whole spine in an automotive seated posture by analyzing image data acquired with an upright open MRI system. Five female and three male asymptomatic subjects were scanned in seated and supine postures, and midsagittal images were analyzed in the location of the center of vertebral body and the vertebral angle relative to lower adjacent vertebra from C2 to sacrum. Results showed that 1) females were more likely to have non-lordosis than males, 2) lumbar lordosis was larger for females than males, and sacrum slope was greater for males than females, 3) thoracic kyphosis and T1 slope were greater for the cervical lordotic type than kyphotic type in seated posture

Analysis of the Alignment of Whole Spine in Automotive Seated and Supine Postures Using an Upright Open MRI System

The purpose of this study is to provide the alignment of whole spine in an automotive seated posture by analyzing image data acquired with an upright open MRI system. Five female and three male asymptomatic subjects were scanned in seated and supine postures, and midsagittal images were analyzed in the location of the center of vertebral body and the vertebral angle relative to lower adjacent vertebra from C2 to sacrum. Results showed that 1) females were more likely to have non-lordosis than males, 2) lumbar lordosis was larger for females than males, and sacrum slope was greater for males than females, 3) thoracic kyphosis and T1 slope were greater for the cervical lordotic type than kyphotic type in seated posture

Investigation of Whole Spine Alignment Patterns in Automotive Seated Posture Using Upright Open MRI Systems

The purpose of this study is to investigate whole spinal alignment patterns in an automotive seated posture. Image data sets of eight female and seven male seated volunteers were acquired using upright open Magnetic Resonance Imaging systems. The images were processed to extract the whole spine alignment defined with the centres of the vertebral bodies. Patterns of the whole spine alignment were investigated through Multi‐Dimensional Scaling analyses. The analysis revealed that variations in the whole spine alignment due to individual differences were seen most remarkably in the combination of curvature of the cervical spinal alignment and degree of the thoracic kyphosis with its peak vertebra level. Subjects with cervical lordosis tended to have a pronounced thoracic kyphosis, with the peak of this kyphosis located at a lower vertebra level. Subjects with cervical kyphosis tended to have a less pronounced thoracic kyphosis, with the peak of this kyphosis at a higher vertebra level. These trends were also observed in the differences of average spinal alignments between males and females