Morphometric characteristics of cryopreserved mesencephalic dopamine neurons in culture

Interactive image analysis programs for quantifying injury-induced axonal beading and microtubule disruption

Focal axonal beading and focal disruption of microtubule structure are characteristic to traumatic axonal injury. We have recently reproduced these morphological and structural changes in our in vitro model system [D. Kilinc, G. Gallo, K.A. Barbee, Mechanically induced membrane poration causes axonal beading and localized cytoskeletal damage, Exp. Neurol. 212 (2008) 422-430]. In order to measure bead formation objectively, an observer-independent quantification of beading was necessary. In addition, a quantitative measure for the extent of co-localization of axonal beads and microtubule disruptions was required to establish a causal relationship between focal cytoskeletal damage and bead formation. In this paper we describe Matlab-based, interactive image analysis programs for axonal beading quantification and co-localization analysis. Injury-induced increases in the axonal beading could be successfully detected using the bead analysis program.

A human spinal cord cell promotes motoneuron survival and maturation in vitro

Primary cultures of motoneurons represent a good experimental model for studying mechanisms underlying certain spinal cord pathologies, such as amyotrophic lateral sclerosis and spinal bulbar muscular atrophy (Kennedy's disease). However, a major problem with such culture systems is the relatively short cell survival times, which limits the extent of motoneuronal maturation. In spite of supplementing culture media with various growth factors, it remains difficult to maintain motoneurons viable longer than 10 days in vitro. This study employs a new approach, in which rat motoneurons are plated on a layer of cultured cells derived from newborn human spinal cord. For all culture periods, more motoneurons remain viable in such cocultures compared with control monocultures. Moreover, although no motoneurons survive in control cultures after 22 days, viable motoneurons were observed in cocultures even after 7 weeks. Although no significant difference in neurite length was observed between 8-day mono- and cocultures, after 22 and 50 days in coculture motoneurons had a very mature morphology. They extended extremely robust, very long neurites, which formed impressive branched networks. Data obtained using a system in which the spinal cord cultures were separated from motoneurons by a porous polycarbonate filter suggest that soluble factors released from the supporting cells are in part responsible for the beneficial effects on motoneurons. Several approaches, including immunocytochemistry, immunoblotting, and electron microscopy, indicated that these supporting cells, capable of extending motoneuron survival and enhancing neurite growth, had an undifferentiated or poorly differentiated, possibly mesenchymal phenotype.

Cryopreservation and primary culture of cerebral neurons from cynomolgus monkeys (Macaca fascicularis)

We established the procedures for cryopreservation and primary culture of fetal cerebral neurons of cynomolgus monkeys (Macaca fascicularis). Three developmental stages of fetuses (80, 93, and 102 days of gestation) were compared to determine the optimal stage of cerebrum development for primary culture. Among the three fetuses, the 80-day-old fetus produced the most process-rich neurons with the highest survival. The number of total recovery cells from the cryopreserved 80-day-old fetus corresponded to 83.4% of that from fresh tissue. Besides, synchronous oscillations of intracellular calcium were first seen in primate cerebral neurons, which suggested the formation of synapse-networks. Cultured neurons expressed synaptophysin protein. Successful cryopreservation and subsequent cell culture of primate neurons would be useful tools for neuroscience research with species specificity.

Cryopreservation of brain tissue for primary culture

Factors affecting recovery of brain cells from cryopreserved cerebral tissues of fetal rats were examined based on yields of viable cells on cell culture. Favorable preservation was obtained with freezing small pieces (less than 1 mm cube) of brain tissues rather than whole tissues or dissociated single cells, and use of 10% dimethylsulfoxide as a cryoprotectant in liquid nitrogen. As for cell preparation procedures, cell survival was improved when tissues were heated at 32 degrees C during papain digestion and centrifugation. Under favorable conditions, the number of brain cells recovered from cryopreserved tissues corresponded to 20-30% of those from fresh control tissues. Immunocytochemical characteristics of cultured neurons, astrocytes, and oligodendrocytes from cryopreserved and fresh tissues were indistinguishable. Semi-quantitive analyses of microtubule-associated protein-2 (MAP-2) and synaptophysin revealed that there was no difference in the amounts of these markers between cultures from both fresh and cryopreserved tissues. These results suggest that most of all cell types including neurons were equally susceptible to the cryopreservation procedures. We concluded that cryopreservation in liquid nitrogen is an effective method for preservation of embryonic brain tissues for later use in cell culture studies.