The Kindling Model of Temporal Lobe Epilepsy
Steven L. Peterson, Timothy E. Albertson in Neuropharmacology Methods in Epilepsy Research, 2019
Two systems exist for determining the relative position of a structure within the rat brain. The original system utilized the interaural line as the basis of determining the stereotaxic coordinates. The interaural line refers to a line through the head of the rat from one auditory meatus to the other. In the second system, bregma is used as the major reference. As indicated in Figure 3.2A, bregma is the point of intersection of the coronal skull suture with the midline or saggital suture. Most recent atlases provide coordinates for both systems so that the investigator can use either point of reference. Advantages to using bregma are (1) it is visible during surgery, and (2) greater accuracy is achieved when using rats of different sizes.17,20 Whishaw et al.20 also reported greater accuracy with bregma when the anatomical structure of interest is located anterior to this reference point. Although Paxinos and Watson11 confirmed this finding, they also noted that the interaural reference point may be better suited for localizing more posterior structures.
Morphometries of Craniofacial Form
D. Dixon Andrew, A.N. Hoyte David, Ronning Olli in Fundamentals of Craniofacial Growth, 2017
Considerable controversy surrounds these two contrasting definitions of homology, i.e., one geometric and the other biologic (O’FIiggins and Johnson, 1988). That is, can homologous points even be related to changes in homologous structures? Comparison of forms, based only on a few homologous landmarks, can lead to the misleading conclusion that little in the way of changes in size and shape are present (due to growth, phylogeny, teratology, etc.) because the two landmarks are only slowly changing, in contrast to rapid change of the form between the landmarks. Alternatively, the question arises whether relative shifts in landmark position between forms are subject to the processes of growth, evolution or other factors, or are they just being carried along by alterations in the broader aspects of the form itself? For example, within the craniofacial complex, there are certain landmark locations that are largely independent of the curvature in which they are embedded. Consider the variability in the position of bregma in relationship to the parietal bones of the cranial vault as viewed in the sagittal aspect (see Figure 1 in O’Higgins and Johnson, 1988). This suggests that major changes in homologous points could occur between forms, while those homologous structures (in which the points are embedded) may represent states; that is, be stable and unchanging for long periods of time. Given the complex ways in which the shapes of organisms are altered with growth and other forces, limiting one’s analysis to homologous landmarks may not be the most optimal way of extracting the biologically relevant information that resides in the form.
Head and Neck
Rui Diogo, Drew M. Noden, Christopher M. Smith, Julia Molnar, Julia C. Boughner, Claudia Barrocas, Joana Bruno in Understanding Human Anatomy and Pathology, 2018
The skull cap, formed by parts of the frontal, parietal, and occipital bones, is called the calvaria. The cranial bones are joined by sutures, which are immobile joints of interlocking bone. The parietal bone includes the posterior portions of the superior and inferior temporal lines. The suture between the parietals and the occipital bone—which contains the external occipital protuberance—is called the lambdoid suture (not because of anything to do with young sheep, but because the suture’s path resembles the divergent shape of the Greek letter, lambda). The point where this suture meets the sagittal suture (named of course for its position in the sagittal plane; see Figure 2.1) separating the left and right parietal bones, is called lambda (Plate 3.7b). The suture between the parietals and the frontal bone is called the coronal suture (because of the suture’s position in the coronal plane). The area where the sagittal and coronal sutures meet is called bregma, an odd-sounding moniker that apparently denoted the top of the head to the ancient Greeks who named this skull landmark. The intersection of the frontal, sphenoid, temporal, and parietal bones is called the pterion, which exhibits at least four variations in terms of which of these four bones contact each other. The suture between the temporal and parietal bones is called the squamosal (it’s a stretch to imagine but this name derives from “plate” or “scale”-like, because the suture separates the parietal bone from the squamosal region of the temporal bone; this region contrasts with the petrous, or “stone-like,” region of the temporal bone) suture (Plate 3.8a).
Intranasal administration of dauricine loaded on graphene oxide: multi-target therapy for Alzheimer's disease
Published in Drug Delivery, 2021
Kaixuan Wang, Lingfeng Wang, Ling Chen, Chiwei Peng, Beijiao Luo, Jingxin Mo, Wei Chen
The AD model was established by subjecting mice to an intracerebroventricular injection of aggregated Aβ1-42 (1 μg/μL) using a microinjector. Mice were anesthetized by an intraperitoneal injection of pentobarbital (0.4 g/kg body weight) and mounted on a stereotaxic frame (Stoelting, Wood Dale, IL). An incision was made in the skull along the cranial midline sagittal line to expose bregma completely. The location of the injection site was verified according to The Mouse Brain in Stereotaxic Coordinates, second edition: 2 mm posterior to the bregma, 1.5 mm from the biparietal suture, and 2 mm under the skull. Five microliters saline or aggregated Aβ1-42 (1 μg/μL) was injected into the brain using a microinjector over 5 min. After injection, the needle was left in place for another 5 min, and then pulled out slowly. The mice were given one day to recover, after which they were intranasally administrated with the appropriate drugs every other day.
Ventral tegmental area inactivation alters hormonal, metabolic, and locomotor responses to inescapable stress
Published in Archives of Physiology and Biochemistry, 2019
Samaneh Mortazaei, Hedayat Sahraei, Zahra Bahari, Gholam Hossein Meftahi, Gila Pirzad Jahromi, Boshra Hatef
Animals were anesthetized with ketamine (75 mg/kg) and diazepam (5 mg/kg) and were placed in a stereotaxic frame (Stoelting, Wood Dale, IL), later a small incision was made in the scalp to expose the skull. Using Bregma and lambda as landmarks, the skull was leveled in the coronal and sagittal planes. Bilateral cannula were implanted in the skull at the anteroposterior (in reference to bregma) and the mediolateral coordinates that correspond to the VTA (4.5 mm anteroposterior [AP], ± 0.8–1 mm mediolateral [ML], and 7.7–8-1 mm [DV] based on the Paxinos and Watson’s atlas (2007). The rats were prepared with one or two stainless steel 23 gauge cannulas placed above the VTA. At the end of the surgery, removable wire styles (30 gauge) were inserted in the cannula to maintain patency. The cannula were permanently secured to the skull by using dental acrylic cement. The animals were given seven days to recover after the surgery. Dental needles head No. 30 (Alibaba; INTR), polyethylene tubes, and 10 µL Hamilton syringes were used for injection. Lidocaine hydrochloride (2%; dissolved in sterile saline) was administered uni- (0.5 µl/rat) or bilaterally (0.25 µl/side) into the VTA by 30-gauge blunts tapered needle at a rate of 0.5 µl/min, 20 min prior to the stress induced. The injection needle was left in place for five min after injection to allow diffusion from the injector tip and the animals were free to move during this time.
Accurate Neurosurgery for the Establishment of the Electric Kindling Model of Epilepsy in Mice
Published in Journal of Investigative Surgery, 2022
Verónica Custodio, Jorge Acosta, Carmen Rubio, Leonardo Hernández, Javier Brito, Elisa Taddei
Once the mouse is anesthetized, it is placed in the stereotaxic equipment (David Kopf equipment), on a thermostatically-controlled heating blanket and fitted with a rectal temperature probe for monitoring body temperature.The tip of auditory bars must be inserted in the auditory meatus of each ear, locating the head of the mouse in the center, at an equidistant position. The plug of auditory meatus must be performed carefully to avoid fractures in the ear bones, and the maximum pressure of the auditory bars must not exceed 2 g per side.The incisive teeth of the mouse must be fixed using the bite bar of the stereotaxic equipment, ensuring that the head is fully fixed and immobile (Figure 6a). The incisor bar establishes the inclination of the mice head in a flat-skull position. The two reference points on the skull bregma and lambda (point of intersection of the lines passing through the sagittal suture and the left and right portions of the lambdoid suture), are both kept in the same horizontal plane using the incisor bar.
Related Knowledge Centers
- Anterior Fontanelle
- Birth Defect
- Coronal Suture
- Parietal Bone
- Calvaria
- Frontal Bone
- Brain
- Sagittal Suture
- Cleidocranial Dysostosis
- Stereotactic Surgery