The video discusses a surgical procedure for implanting bone screws in a mouse's skull. It covers preparation steps, locating screw placement, scoring the skull, and applying liquid cyanoacrylate to secure the screws while avoiding damage to the underlying dura, ensuring the success of the micro drive implant.

surgical implantation of the micro-drive on the mouse skull

Implante Micro-Drive para Registro da Atividade Neural Diária em Camundongos Juvenis

The brain undergoes large-scale changes during the critical developmental windows of childhood and adolescence1,2,3. Many neurologic and psychiatric diseases, including autism and schizophrenia, first manifest behaviorally and biologically during this period of juvenile and adolescent brain development4,5,6. While much is known regarding the cellular, synaptic, and genetic changes that occur across early development, comparatively little is known regarding how circuit- or network-level processes change throughout this time window. Importantly, circuit-level brain function, which ultimately underlies complex behaviors, memory, and cognition, is a non-predictable, emergent property of cellular and synaptic function7,8,9,10. Thus, to fully understand network-level brain function, it is necessary to directly study neural activity at the level of an intact neural circuit. In addition, to identify how brain activity is altered throughout the progression of neuropsychiatric disorders, it is critical to examine network activity in a valid disease model during the specific temporal window when the behavioral phenotypes of the disease manifest and to track the observed changes as they persist into adulthood.
One of the most common and powerful scientific model organisms is the mouse, with large numbers of unique genetic strains that model neurodevelopmental disorders with age-dependent onset of the behavioral and/or mnemonic phenotypes11,12,13,14,15,16,17,18,19,20,21. While it is challenging to correlate precise developmental time points between the brains of humans and mice, morphological and behavioral comparisons indicate that p20-p21 mice represent the human ages of 2-3 years old, and p25-p35 mice represent the human ages of 11-14 years old, with mice likely reaching the developmental equivalent of a human 20 year old adult by p603,22. Thus, to better understand how the juvenile brain develops and to identify how the neural networks of the brain become dysfunctional in diseases like autism or schizophrenia, it would be ideal to directly monitor brain activity in vivo in mice across the ages of 20 days to 60 days old.
However, a fundamental challenge in monitoring brain activity across early development in mice is the small size and relative weakness of juvenile mice. The chronic implantation of electrodes, which is necessary for longitudinal studies of brain development, typically requires large, bulky housing to protect the fine electrode wires and interface boards23,24, and the implants must be firmly attached to the mouse skull, which is thinner and less rigid in young mice due to reduced ossification. Thus, virtually all studies of in vivo rodent physiology have been performed in adult subjects due to their relative size, strength, and skull thickness. To date, most studies exploring in vivo juvenile rodent brain physiology have been performed in wild-type juvenile rats, which necessarily limits the ability to experimentally monitor juvenile brain function in a freely behaving model of a human disorder25,26,27,28,29,30.
This manuscript describes novel implant housing, a surgical implantation procedure, and a post-surgery recovery strategy to chronically study the long-term (up to 4 or more weeks) in vivo brain function of juvenile mice across a developmentally critical time window (p20 to p60 and beyond). The implantation procedure allows for the reliable, permanent affixation of the electrodes to the skulls of juvenile mice. Furthermore, the micro-drive design is lightweight, as this micro-drive weighs ~4-6 g when fully assembled, and due to the minimal counterbalancing required to offset the weight of the implant, it does not impact the behavioral performance of juvenile mice during typical behavioral paradigms.

Autor em destaque: um implante de acionamento leve para gravações crônicas de Tetrode em camundongos juvenis  

Um implante de acionamento leve para gravações crônicas de tetrodo em camundongos juvenis

Watch this Scientific Journal Video about Surgical Implantation of the Micro-Drive on the Mouse Skull at JoVE.com

Surgical Implantation of the Micro-Drive on the Mouse Skull  

Implante Cirúrgico do Micro-Drive no Crânio de Camundongos

Depois de preparar o mouse para a cirurgia e expor o crânio, coloque os parafusos ósseos nas porções laterais, rostral ou caudais extremas do crânio, onde o osso é mais espesso e os parafusos ósseos estão suficientemente longe do implante de micro drive. Use uma lâmina de bisturi ou broca para marcar o crânio perto dos locais do orifício do parafuso ósseo, fornecendo uma superfície áspera para o cianoacrilato líquido se ligar. Em seguida, rosqueie cada parafuso ósseo no lugar, com cuidado para não perfurar a dura-máter subjacente.Com agulha estéril de calibre 30, aplique cianoacrilato líquido ao redor de cada parafuso ósseo, espessando o crânio onde os parafusos ósseos foram fixados. Certifique-se de que nenhum cianoacrilato entre na dura-máter exposta acima dos locais de gravação.

surgical-implantation-of-the-micro-drive-on-the-mouse-skull

Research

JoVE Journal

Neuroscience

Surgical Implantation of the Micro-Drive on the Mouse Skull

542 visualizações. Depois de preparar o mouse para a cirurgia e expor o crânio, coloque os parafusos ósseos nas porções laterais, rostral ou caudais extremas do crânio, onde o osso é mais espesso e os parafusos ósseos estão suficientemente longe do implante de micro drive. Use uma lâmina de bisturi ou broca para marcar o crânio perto dos locais do orifício do parafuso ósseo, fornecendo uma superfície áspera para o cianoacrilato líquido se ligar. Em seguida, rosqueie cada parafuso ósseo no lugar,...

Vídeo: Surgical Implantation of the Micro-Drive on the Mouse Skull  

A Lightweight Drive Implant for Chronic Tetrode Recordings in Juvenile Mice

In vivo electrophysiology provides unparalleled insight into the sub-second-level circuit dynamics of the intact brain and represents a method of particular importance for studying mouse models of human neuropsychiatric disorders. However, such methods often require large cranial implants, which cannot be used in mice at early developmental time points. As such, virtually no studies of in vivo physiology have been performed in freely behaving infant or juvenile mice, despite the fact that a better understanding of neurological development in this critical window would likely provide unique insights into age-dependent developmental disorders such as autism or schizophrenia. Here, a micro-drive design, surgical implantation procedure, and post-surgery recovery strategy are described that allow for chronic field and single-unit recordings from multiple brain regions simultaneously in mice as they age from postnatal day 20 (p20) to postnatal day 60 (p60) and beyond, a time window roughly corresponding to the human ages of 2 years old through to adulthood. The number of recording electrodes and final recording sites can be easily modified and expanded, thus allowing flexible experimental control of the in vivo monitoring of behavior- or disease-relevant brain regions across development.

Here, we describe a micro-drive design, surgical implantation procedure, and post-surgery recovery strategy that allow for chronic field and single-unit recordings from multiple brain regions simultaneously in juvenile and adolescent mice across a critical developmental window from postnatal day 20 (p20) to postnatal day 60 (p60) and beyond.