Transmission Mission

Answer:

LOCOEMOTION

You can start by filling in the crossword. Most clues are brain/emotion-themed, and a few are Inside Out references (which should hopefully be easily searchable). The complete grid is shown here:

No.	Clue	Answer	Comments
1→	Main inhibitory molecule	GABA
3→	What San Francisco ruined pizza with	BROCCOLI	"Pizza" Clip
6→	A jellyfish doesn't have this	BRAIN
8→	Brain squiggle hills	GYRI
9→	Plays an important role in 2 down and 12 across	AMYGDALA
11→	Last thing remaining in Pandora's box	HOPE
12→	Who said, "All right! We did not die today, I call that an unqualified success."	FEAR	Clip
14→	Taking a trip in your sleep?	DREAMING	Enables you to take trips (anywhere!) in your sleep
15→	Build, change, or grow	DEVELOP
16→	Enveloped by myelin sheath	AXON
19→	They powered different aspects of Riley’s personality	CORE MEMORIES	"Riley's Memories" Clip
21→	Toast, praise, or uplift	CHEER
22→	Audible amusement	LAUGH
23→	Basic brain unit	NEURON
24→	Buildup of this leads to edema	FLUID
26→	What Joy makes you do	SMILE
28→	_____ of Thought	TRAIN	Wiki
29→	Brain squiggle valleys	SULCI
30→	Half of the world inside your head?	HEMISPHERE	May refer to two halves of the Earth as well as the two halves of your cerebrum.
31→	Who said, "Say what you want, I think it's all beautiful."	JOY	Clip
32→	Who said, "Fashion island! Everyone shut up."	DISGUST	Clip
33→	They came to help because of her	SADNESS	Clip
2↓	Who yelled, "Did I ask for the gum commercial?!"	ANGER	Clip
4↓	Land where you can construct your perfect boyfriend!	IMAGINATION	Clip
5↓	ATP	ENERGY
7↓	Activates muscles and plays a major signaling role in ANS. (And may also be found in a sneeze?)	ACETYLCHOLINE	Its abbreviation (ACh) can be found in "Achoo!"
10↓	Shady matter?	GRAY	Refers to "gray matter"; gray is also a shade
11↓	Mission control for 2 down, 12 across, 31 across, 32 across, and 33 across	HEADQUARTERS	Wiki
13↓	Plays an important role in memory formation, especially for sea monster horses?	HIPPOCAMPUS	The hippocampus, or hippokampos (hippos, meaning “horse,” and kampos, meaning “sea monster”), is a mythological creature shared by Phoenician, Etruscan, Pictish, Roman and Greek mythology. The hippocampus brain region derives its name from its similarity in shape to seahorses.
14↓	A dope molecule produced abundantly in Pavlov's dogs?	DOPAMINE	Its first syllable is literally "dope"
17↓	L'émotion derrière "je t'aime"	AMOUR	The emotion behind "I love you", in French
18↓	A water balloon carrying important information across 20 down?	VESICLE	It's a small "fluid-filled sac," so quite literally a water balloon.
20↓	The spaces between neurons (or, the setting for this puzzle?)	SYNAPSES	The drawing above is a representation of a synapse: the top blue piece is the axon terminal, the bottom blue piece is the dendrite, and the space where the crossword sits is the synaptic cleft.
25↓	Irritate	ANNOY
27↓	A type of 14 across in which you are aware	LUCID	Refers to "lucid dreaming"

The next step is to figure out what to do with the given pipes. There are 8 tubes above and 8 tubes below the crossword, each with a bit of pipe sticking out. As clued by the flavortext, we'll need to "re-pair" each of the molecules at the top with one of the corresponding memories at the bottom by connecting each pair with one of the pipes.

But what are these molecules? They're neurotransmitters (clued by "nervous... transmit her"; "nervous" refers to "nervous system," and "transmit her" sounds like "transmitter")! Each neurotransmitter has a particular abbreviation (clued by "short on," which sounds like "shorten"). Taking the first letter of each word in any memory (clued by "first") yields a neurotransmitter abbreviation. Each neurotransmitter's memory is furthermore related to one of the neurotransmitter's major functions. The table below summarizes the pairings:

Molecule		Neurotransmitter		Memory		Function		Pipe
		Adrenaline, Ad (aka Epinephrine, Epi)				Increases heart rate, which may happen during an Active drama performance
		Norepinephrine, NE (aka Noradrenaline, NAd)				Acts as a stress (Nervous Energy) hormone
		Dopamine, DA				Contributes to reward-motivated behavior and feelings of pleasure, such as from Developing Avocation (avocation = hobbies)
		Serotonin, 5-HT (aka 5-hydroxytryptamine)				Stabilizes mood and gives feelings of happiness, like going on a 5th Hawaii Trip!
		Gamma-aminobutyric acid, GABA				Reduces stress and increases relaxation, as if you were Gently Admiring Beach Ambience
		Acetylcholine, ACh				Plays roles in arousal, attention, motivation, and is also used in the digestive system to Actively Chomp hamburgers
		Glutamate, Glu or E				Plays an important role in learning and memory needed to Gain lecture understanding
		Histamine, H				Released in response to injury and Hurting

After installing each pipe in the synapse, you should notice that there are only a handful of crossword squares that are intersected by more than one pipe. Reading these letters from left to right, we spell out LOCOEMOTION, a pun on locomotion ("movement") and reads literally as loco ("crazy") emotion.

Authors' Notes

This was the first puzzle we wrote, and probably also the most challenging to create. This puzzle went through the most iterations, probably in part due to the fact that the pieces of our hunt hadn't clicked together yet at the time we finished this puzzle.

We really wanted to include a bio-themed puzzle in our hunt, and what better film to mobilize this than Inside Out?

The flavor of this puzzle comes from how synapses work in real life. Impulses pass between the axon terminal of one neuron and the dendrite of the target neuron by diffusion of neurotransmitters. In our analogy, we send little orbs down pipes to the other side, inspired by this clip of how memories work in Riley's head. Neurotransmitters play large roles in how we feel and behave, so in this puzzle, we have solvers "install" the right neurotransmitters into relevant memories. In order to remove ambiguity, phrased the memories to match their respective neurotransmitters' abbreviations.

We hope you enjoyed this complex, but colorful puzzle and maybe learned a biology fact or two!