Fetal Brain Development Explained!

2 teachers like this lesson
Print Lesson

Objective

To describe the genetic and environmental factors that impact fetal brain development during its gestational period.

Big Idea

Healthy brain development is a product of both genetic and environmental factors!

Introduction

Lesson Background & Justification:

        Beyond the specialization of nerve tissues from embryonic stem cells, the fetus's brain needs to accomplish a multitude of developmental milestones in vivo before it is properly structured to process environmental cues postnatal. Key to these events is the process of of nerve cells moving into its proper orientation to pursue a lifelong task or Neuronal Migration. In this lesson, students learn to not only sequence these migratory events but learn to attach their relationship to earlier embryonic specialization events as well as their significance to postnatal events such as Critical Periods (a period of critical experiences for growth), Plasticity (the ability for the brain to modify itself.).   

Instructor's Note:

       This lesson is divided into two ninety minute instructional blocks. Day one, this lesson, addresses the Engagement, Exploratory and the Explanation areas of the 5E Model Lesson Plan. The second day addresses the second half of the 5E Model specifically, the Extension and Evaluation activities.

Lesson Preparations:

 In the effort to prepare for this lesson, I make certain that I have the following items in place: 

a) A class set of Science Take-Out's Birth Defects and Folic Acid Kit. I obtain one kit for each pair of students.

b) Set of fetal brain development matching cards for every pair of students. 

e) A class set of rulers and scissors.

f) Student lab books.

Common Core and NGSS Standards:

SP4- Analyzing and interpreting data.

SP2- Developing and Using Models.

HS-LS1-1-Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out essential functions of life through systems of specialized cells. 

HS-LS1-4-Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms.

W.11-12.1- Write arguments to support claims in an analysis of substantive topics or texts, using valid reasoning and relevant and sufficient evidence.

Standards Rationale:

       In the science classroom, students are regularly charged with tasks to collect and make sense of data from readings and investigations. What makes these science experiences powerful enough to retain however, is an instructor's ability to access, stimulate and develop students' higher order thinking capacities for cognitive growth and subsequently establishing sound learning practices. In this lesson, students learn to use simulation modeling as a visual reference for a microscopic process and use information collected to provide evidences for argumentation. Subsequently, they learn to argue the validity of a scientific claim through scientific investigation, data collection and analysis therein. This aforementioned skill set is essential to science lessons because they offer students an opportunity to systematically approach everyday claims, the basis of science. It also establishes a framework for students to handle open inquiry and use evidence as support of claims made within their future investigations.  Furthermore, students learn to extract and develop significance of data collected within this framework with the aid of graphic organizers and are better suited to think critically about their work as a final result. 

Engage

15 minutes

Section Primer:         

           Autism: Autism is a neuro-development disorder characterized by impaired social interaction, verbal and non-verbal communication, and by restricted and repetitive behavior. This affliction as it is a growing epidemic in the US is discussed by students and instructor for the lesson's catalyst and serves as a conduit into the exploration activity which expounds upon early development of the brain. This discussion's abridging context sets the stage for students to ask questions about autism and to stimulate students to ponder where in early development might we prevent the condition.  

Section Instructional Sequence:

          In this section of the lesson, my goal is to get students to think about the nature of neurological disorders and why they may continue to persist. Using a combination of video and discussion students are directed to ponder what events and/or processes in fetal brain development contribute to the presence of specific conditions, like autism. I present this activity in the following sequence:

a) I advance to slide 1 of the Brain Development power point presentation and read the first question presented aloud. I then verbally involve students by adding; "What is your understanding of this term?" 

b) I continue to mobilize the next term on the screen and verbally tell students that we are now going to gain a little more insight on the condition but from a parent of an autistic child view. I then click the hyper-linked term to play the following video clip:

 c) At the conclusion of the video clip, I continue to advance the image of the graph on the screen and instruct the students to share what the graph tells us about the condition that we have been discussing and viewing. I allow for students to verbally share ideas with the class for roughly 2-3 minutes before displaying and reading the final rhetorical question presented on slide 2. 

d) I move to the next slide and tell students that in order for us to address this question that we have to understand the processes involved in fetal brain development. I continue by stating "Let's review what we know about early development" and instruct for students to properly identify the terms and functions associated with the letters of the diagram presented. 

e) Next, I display the succeeding image (complete nervous system) and state to the class that this is our well organized end product in which the condition autism exist. I continue; "When do you think that problem associated with autism may develop?", while pointing to each image one at a time. I give students ample time to respond before moving to the next step.

f) Finally, I display the double arrow on the slide and ask if there is more to learn between these two stages before making a final opinion of when autism appears. After taking a few responses from students and displaying the word objective on the slide, I verbally state to the class that learning this is our objective for the lesson. 

Standards Covered:

SP4- Analyzing and interpreting data.

HS-LS1-4-Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms.

Explore

50 minutes

Section Primer:         

           The nervous system is a highly branched and specialized set of organs and tissues which is a product of an organism's genetic code (DNA and its Protein Products) and environmental factors. In early developmental stages, Folic Acid or vitamin B, a water soluble supplement helps the embryo to make healthy new cells (particularly spine and brain in embryos). In this section of the lesson, students examine the stages of nervous tissue development during and beyond the Gastrula Stage (early multicellulr embryo, composed of two or more germinal layers of cells from which the various organs later derive.) and explore the impact of specific environmental factors in the developmental events post-gastrulation.  

Section Instructional Sequence:

          In this section of the lesson, my goal is to give students  an opportunity to acquire an understanding of how preliminary brain structures  are formed in early embryonic development  via a simulation exercise. While engaged in said activity, students learn to assert the primary factor (genetic or environmental) responsible for one stage of development versus another). The idea is for students to understand that both are critical for early brain development of humans. I present this activity in the following sequence:

a) I advance to slide 4 of the presentation and announce to students that we are now going to explore a little more about processes involved with advancing a fetus from the gastrula stage to the fully developed nervous system. I continue to say that we will do this through a claim/evidence format.

b) I then display and read the claim on the slide before instructing students to consider this claim as they move through specified parts of the lab that they are preparing to perform. As I continue to the next slide, I instruct for students to record the evidence chart in their lab books under today's date and the words exploration activity. 

c) As students are writing, I pass out the lab kit: "Science Take Out Birth Defects and Folic Acid" (1 per student pair) and instruct for students to not open the kits until prompted to do so. 

d) Finally, I explain to students how to fill out the chart and direct their attention to the specific parts of the activity that are to be completed and are listed in the first column of the chart. Once students are comfortable with the general set of instructions, I share that lab specifics are recorded on the lab handout and that all responses to these specific tasks are to be listed in their lab book as well. I grant students time to complete the assigned tasks and to discuss their chart recordings as a class.

         While students work on their task, I circulate around the room to clarify their understanding of sections presented or to redirect their attentions to the task at hand should they become sidetracked. 

Standards Covered:

SP4- Analyzing and interpreting data.

SP2- Developing and Using Models.

HS-LS1-1-Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out essential functions of life through systems of specialized cells. 

HS-LS1-4-Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms.

W.11-12.1- Write arguments to support claims in an analysis of substantive topics or texts, using valid reasoning and relevant and sufficient evidence.

Explain

20 minutes

Section Primer:     

           Neuronal Migration is a fundamental process that determine the final allocation of neurons in the nervous system, establishing the basis for the subsequent wiring of neural circuitry. In this section of the lesson, students build on their previous experiences by adding neuronal migration process events on to their explanations of neural tube development events (completed in the exploratory section). In doing so, students learn to explain how this rudimentary structure (neural tube) grows and stabilizes into a mature nervous system but only when primed with the series of events outlined in migration.  

Section Instructional Sequence:

          In this section of the lesson, my goal is for students to apply specific terminology of embryonic brain development to the processes modeled and simulated in the exploration stage of the lesson. I present this activity in the following sequence:

a) I advance to slide 6 and verbally announce to students that we are now going to learn how to explain what we just experienced as well as explain proceeding steps in embryonic nervous system development. I iterate that we are still attempting to explain the events in the space indicated by the double sided arrow seen earlier in the lesson through concept maturation. I further explain that we will use a video to provide a visual on these processes and that we will use a card set to build the timeline of these significant brain developing events represented in the video while it is in motion.

b) Next, I display the two phrases "Time Period" and "Activity Description" on the screen and verbally explain as I pass out the card sets that they are receiving a set of mixed cards which will represent time periods in gray and process descriptions in yellow and that they will use both to build a timeline as they view the following video:

Note: Prior to playing the video, I verbally assert to students that they should take time to view their cards before beginning. I pass out the card sets to student pairs, allow time for student viewing prior to the video presentation. While the video is playing, I permit for students to rewind parts of the video at will to better construct their timelines as I circulate around the classroom for assistance when requested. 

c) Upon the completion of sequencing their timelines, I review students' work by the pair before reviewing the accurate timeline with the class as a whole via general classroom discussion and presentation of the correct responses on slide 7. I specifically aim to bridge students understanding of displayed events to those that preceded. I ask questions such as "If I lowered the amount of sonic hedge hog chemical presented to the blastula ball, how would this impact the brain's developmental events sequenced here?"

d) Finally, we wrap up by hypothesizing and verbally articulating at what point in early fetal brain development do students believe that autism can be prevented. Students are encouraged to make an informed guess based on the information gathered from all sections presented in the lesson. These responses are ultimately recorded in their lab books to revisit in the second day of the lesson.  

Standards Covered:

SP2- Developing and Using Models.

HS-LS1-1-Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out essential functions of life through systems of specialized cells.